There are several references in Scripture to people who were once saved and fell from that salvation.
Just one of many is found in 2 Pet. 2:1: But false prophets also arose among the people, just as there will also be false teachers among you, who will secretly introduce destructive heresies, even denying the Master who bought them, bringing swift destruction upon themselves.
You see that they had once been 'bought', ransomed, purchased. And yet through heresy and denial of the Truth of the Covenant, they bring Perdition upon themselves. The only thing required to lose Covenant Salvation is to deny the Covenant and be unfaithful to it.
Covenant involves two, not one. We stand by Faith. And when that Faith is no longer there, we no longer stand.
Salvation is conditional. The condition is faithfulness to the covenant even as Christ was faithful to the covenant.
But Christ as a son over his own house; whose house are we, if we hold fast the confidence and the rejoicing of the hope firm unto the end. - Heb. 3:6
Again, Paul writes to Christians in Jerusalem in the Letter to the Hebrews, "Take heed, brethren, lest there be in any of you an evil heart of unbelief, in departing from the living God. But exhort one another daily, while it is called To day; lest any of you be hardened through the deceitfulness of sin. For we are made partakers of Christ, if we hold the beginning of our confidence stedfast unto the end;" -- Heb. 3:12-14
Paul applies the lessons learned of the Jews loosing their Salvation to all Christians as well, and entreats them never to harden their hearts against God as the children of Israel had done in the Wilderness, nor to lose Faith and be deceived through sin. For Salvation is conditioned upon our holding fast to the Confidence in Christ firmly to the End.
Salvation is conditional. It is conditioned upon Faith. It is conditioned upon Faithfulness.
There is no such thing as unconditional salvation or unconditional love. For all things are conditional based upon the conditions of our choices and our will to respond and receive the truth and salvation of Christ. As it is at the beginning of the salvific walk so it is till the end. A personal decision.
Again, Paul writes to Timothy (a Christian and saved), saying, "If we suffer, we shall also reign with him: if we deny him, he also will deny us:" -- 2 Tim. 2:12
So we see how many 'ifs' Scripture using in explaining the conditions of Salvation. NT Salvation is wholly conditional upon faith and faithfulness because Convenant involves two, not one.
Again, Paul writing to the Corinthian Christians (who were in a saved condition) openly states that it is possible to receive the Grace of God that results in futility because of the failure to remain faithful in the New Covenant. And so he entreats them to hold steady in the Grace of God that they had formerly received.
We then, as workers together with him, beseech you also that ye receive not the grace of God in vain. (For he saith, I have heard thee in a time accepted, and in the day of salvation have I succoured thee: behold, now is the accepted time; behold, now is the day of salvation.) -- 2 Cor. 6:1-2
Furthermore, that salvation is conditional upon man's freewill is clear from Rev. 22:17: And the Spirit and the bride say, Come. And let him that heareth say, Come. And let him that is athirst come. And whosoever will, let him take the water of life freely.
If it is conditioned upon 'whosoever will', then the Elect of God are those who choice by freewill.
Again, Paul styles those who were once in a state of salvation, but have failed the test as Reprobates. They were banished once by breaking the law, and yet again they have become 'probates', according to its true and denotative meaning of castaway.
Examine yourselves, whether ye be in the faith; prove your own selves. Know ye not your own selves, how that Jesus Christ is in you, except ye be reprobates? -- 2 Cor. 13:5
However, the greatest example of how one may remain in Christian Salvation or fall from Christian Salvation is given by Christ in the parable. Here Christ speaks of some who were once attatched to the Vine of Christ, but produced bad fruit. They were therefore 'cut off', cast away and summarily burnt in the pires of the autumn harvest.
If a man abide not in me, he is cast forth as a branch, and is withered; and men gather them, and cast them into the fire, and they are burned.-- John 15:6
We can see how important human freewill is in our faith-conditional salvation through grace. Jesus states that it is those who will to do the Thelema Theou (Will of God) who will know of His Teaching.
If any man will do his will, he shall know of the doctrine, whether it be of God, or whether I speak of myself. -- John 7:17
Again, the Gospels reveal over and over the conditional nature of Salvation based upon remaining faithful to the end.
For example, Mark 13:13 reads "And ye shall be hated of all men for my name's sake: but he that shall endure unto the end, the same shall be saved."
This then implies that the one who does endure to the end shall not be saved.
Another issue that can cause people to lose their Salvation is to begin twisting Scripture and teaching false doctrines. Salvation is conditioned upon remainful faithful in the truthful proclamation of the Good Current of Christ.
Peter speaks of some in his time who had brought destruction upon themselves by simply twisting Apostle Paul's Epistles to suit their own ends.
As also in all his epistles, speaking in them of these things; in which are some things hard to be understood, which they that are unlearned and unstable wrest, as they do also the other scriptures, unto their own destruction. -- 2 Peter 3:16
Christ is very bold in his proclamation in Revelation and grants the victory only to the Victor through faithful endurance.
Seven time in Revelation Christ states "To him that overcometh". We overcome and win the Victory of Salvation just as Christ overcame and won the Victory of Salvation. For Christ states, As I overcame, so he shall overcome. And it is by Fidelity to the Covenant to the End.
So, basically, salvation is conditional on faith and faithfulness. And it can be lost or maintained through faithfulness of unfaithfulness to the Covenant.
John relates as much in Revelation 17:14 writing "καὶ οἱ μετ’ αὐτοῦ κλητοὶ καὶ ἐκλεκτοὶ καὶ πιστοί".
Again, Paul writes of the salvation that is based upon continual and enduring Faith in writing to the Roman Christians, saying,
αλλα τι λεγει εγγυς σου το ρημα εστιν εν τω στοματι σου και εν τη καρδια σου τουτ εστιν το ρημα της πιστεως ο κηρυσσομεν οτι εαν ομολογησης εν τω στοματι σου κυριον ιησουν και πιστευσης εν τη καρδια σου οτι ο θεος αυτον ηγειρεν εκ νεκρων σωθηση καρδια γαρ πιστευεται εις δικαιοσυνην στοματι δε ομολογειται εις σωτηριαν λεγει γαρ η γραφη πας ο πιστευων επ αυτω ου καταισχυνθησεται --Romans 10:8-11
However, what does [the Scripture] say? "The Utterance is near you; in your Mouth and in your Heart": this is the Utterance of the Faith that we are Preaching--that if you kept confessing the Lord Jesus with your Mouth and kept believing in your Heart that the Deity raised Him from the Dead, you will be saved. For the Heart keeps believing leading to Justification, and confession keeps being made leading to Salvation. For the Scripture states that all who are believing upon Him shall not be put to Shame.
So you see how Paul entreats to the Christians who had once believed in and confessed Christ to keep believing and confessing, for this would result in their Justification and Salvation. This is a lifelong path and stairway to Heaven by Faith in Jesus Christ.
Again, Paul talks about the Life and Salvation being conditioned upon walking according to the Spirit and not according to the Flesh. For he writes to the Christians in Rome, saying,
Therefore, brethren, we are debtors, not to the flesh, to keep living after the flesh. For if you keep living after the Flesh, you shall die: but if you through the Spirit do mortify the deeds of the body, you shall live. For as many as keep being led by the Spirit of God, they are the Sons of God. -- Rom. 8:13-14
And so to be a Son of God and to have Life implies a continual walk according to the Spirit. Paul flatly tells the Christians at Rome that if they keep living according to the Flesh, they will die. This is not refering to physical death, but spiritual and second death. These are not unsaved people, but the people of the Church of Rome.
Again, in the Epistle to the Church at Ephesus, Paul entreats the saved through Grace by Faith Christians to not take part in the practices of those who suffer the wrath of God lest they sever themselves from the Kingdom of God and their salvation by sin.
But fornication, and all uncleanness, or covetousness, let it not be once named among you, as becometh saints; Neither filthiness, nor foolish talking, nor jesting, which are not convenient: but rather giving of thanks. For this ye know, that no whoremonger, nor unclean person, nor covetous man, who is an idolater, hath any inheritance in the kingdom of Christ and of God. Let no man deceive you with vain words: for because of these things cometh the wrath of God upon the children of disobedience. Be not ye therefore partakers with them. -- Eph. 5:3-7
Just one of many is found in 2 Pet. 2:1: But false prophets also arose among the people, just as there will also be false teachers among you, who will secretly introduce destructive heresies, even denying the Master who bought them, bringing swift destruction upon themselves.
You see that they had once been 'bought', ransomed, purchased. And yet through heresy and denial of the Truth of the Covenant, they bring Perdition upon themselves. The only thing required to lose Covenant Salvation is to deny the Covenant and be unfaithful to it.
Covenant involves two, not one. We stand by Faith. And when that Faith is no longer there, we no longer stand.
Salvation is conditional. The condition is faithfulness to the covenant even as Christ was faithful to the covenant.
But Christ as a son over his own house; whose house are we, if we hold fast the confidence and the rejoicing of the hope firm unto the end. - Heb. 3:6
Again, Paul writes to Christians in Jerusalem in the Letter to the Hebrews, "Take heed, brethren, lest there be in any of you an evil heart of unbelief, in departing from the living God. But exhort one another daily, while it is called To day; lest any of you be hardened through the deceitfulness of sin. For we are made partakers of Christ, if we hold the beginning of our confidence stedfast unto the end;" -- Heb. 3:12-14
Paul applies the lessons learned of the Jews loosing their Salvation to all Christians as well, and entreats them never to harden their hearts against God as the children of Israel had done in the Wilderness, nor to lose Faith and be deceived through sin. For Salvation is conditioned upon our holding fast to the Confidence in Christ firmly to the End.
Salvation is conditional. It is conditioned upon Faith. It is conditioned upon Faithfulness.
There is no such thing as unconditional salvation or unconditional love. For all things are conditional based upon the conditions of our choices and our will to respond and receive the truth and salvation of Christ. As it is at the beginning of the salvific walk so it is till the end. A personal decision.
Again, Paul writes to Timothy (a Christian and saved), saying, "If we suffer, we shall also reign with him: if we deny him, he also will deny us:" -- 2 Tim. 2:12
So we see how many 'ifs' Scripture using in explaining the conditions of Salvation. NT Salvation is wholly conditional upon faith and faithfulness because Convenant involves two, not one.
Again, Paul writing to the Corinthian Christians (who were in a saved condition) openly states that it is possible to receive the Grace of God that results in futility because of the failure to remain faithful in the New Covenant. And so he entreats them to hold steady in the Grace of God that they had formerly received.
We then, as workers together with him, beseech you also that ye receive not the grace of God in vain. (For he saith, I have heard thee in a time accepted, and in the day of salvation have I succoured thee: behold, now is the accepted time; behold, now is the day of salvation.) -- 2 Cor. 6:1-2
Furthermore, that salvation is conditional upon man's freewill is clear from Rev. 22:17: And the Spirit and the bride say, Come. And let him that heareth say, Come. And let him that is athirst come. And whosoever will, let him take the water of life freely.
If it is conditioned upon 'whosoever will', then the Elect of God are those who choice by freewill.
Again, Paul styles those who were once in a state of salvation, but have failed the test as Reprobates. They were banished once by breaking the law, and yet again they have become 'probates', according to its true and denotative meaning of castaway.
Examine yourselves, whether ye be in the faith; prove your own selves. Know ye not your own selves, how that Jesus Christ is in you, except ye be reprobates? -- 2 Cor. 13:5
However, the greatest example of how one may remain in Christian Salvation or fall from Christian Salvation is given by Christ in the parable. Here Christ speaks of some who were once attatched to the Vine of Christ, but produced bad fruit. They were therefore 'cut off', cast away and summarily burnt in the pires of the autumn harvest.
If a man abide not in me, he is cast forth as a branch, and is withered; and men gather them, and cast them into the fire, and they are burned.-- John 15:6
We can see how important human freewill is in our faith-conditional salvation through grace. Jesus states that it is those who will to do the Thelema Theou (Will of God) who will know of His Teaching.
If any man will do his will, he shall know of the doctrine, whether it be of God, or whether I speak of myself. -- John 7:17
Again, the Gospels reveal over and over the conditional nature of Salvation based upon remaining faithful to the end.
For example, Mark 13:13 reads "And ye shall be hated of all men for my name's sake: but he that shall endure unto the end, the same shall be saved."
This then implies that the one who does endure to the end shall not be saved.
Another issue that can cause people to lose their Salvation is to begin twisting Scripture and teaching false doctrines. Salvation is conditioned upon remainful faithful in the truthful proclamation of the Good Current of Christ.
Peter speaks of some in his time who had brought destruction upon themselves by simply twisting Apostle Paul's Epistles to suit their own ends.
As also in all his epistles, speaking in them of these things; in which are some things hard to be understood, which they that are unlearned and unstable wrest, as they do also the other scriptures, unto their own destruction. -- 2 Peter 3:16
Christ is very bold in his proclamation in Revelation and grants the victory only to the Victor through faithful endurance.
Seven time in Revelation Christ states "To him that overcometh". We overcome and win the Victory of Salvation just as Christ overcame and won the Victory of Salvation. For Christ states, As I overcame, so he shall overcome. And it is by Fidelity to the Covenant to the End.
So, basically, salvation is conditional on faith and faithfulness. And it can be lost or maintained through faithfulness of unfaithfulness to the Covenant.
John relates as much in Revelation 17:14 writing "καὶ οἱ μετ’ αὐτοῦ κλητοὶ καὶ ἐκλεκτοὶ καὶ πιστοί".
Again, Paul writes of the salvation that is based upon continual and enduring Faith in writing to the Roman Christians, saying,
αλλα τι λεγει εγγυς σου το ρημα εστιν εν τω στοματι σου και εν τη καρδια σου τουτ εστιν το ρημα της πιστεως ο κηρυσσομεν οτι εαν ομολογησης εν τω στοματι σου κυριον ιησουν και πιστευσης εν τη καρδια σου οτι ο θεος αυτον ηγειρεν εκ νεκρων σωθηση καρδια γαρ πιστευεται εις δικαιοσυνην στοματι δε ομολογειται εις σωτηριαν λεγει γαρ η γραφη πας ο πιστευων επ αυτω ου καταισχυνθησεται --Romans 10:8-11
However, what does [the Scripture] say? "The Utterance is near you; in your Mouth and in your Heart": this is the Utterance of the Faith that we are Preaching--that if you kept confessing the Lord Jesus with your Mouth and kept believing in your Heart that the Deity raised Him from the Dead, you will be saved. For the Heart keeps believing leading to Justification, and confession keeps being made leading to Salvation. For the Scripture states that all who are believing upon Him shall not be put to Shame.
So you see how Paul entreats to the Christians who had once believed in and confessed Christ to keep believing and confessing, for this would result in their Justification and Salvation. This is a lifelong path and stairway to Heaven by Faith in Jesus Christ.
Again, Paul talks about the Life and Salvation being conditioned upon walking according to the Spirit and not according to the Flesh. For he writes to the Christians in Rome, saying,
Therefore, brethren, we are debtors, not to the flesh, to keep living after the flesh. For if you keep living after the Flesh, you shall die: but if you through the Spirit do mortify the deeds of the body, you shall live. For as many as keep being led by the Spirit of God, they are the Sons of God. -- Rom. 8:13-14
And so to be a Son of God and to have Life implies a continual walk according to the Spirit. Paul flatly tells the Christians at Rome that if they keep living according to the Flesh, they will die. This is not refering to physical death, but spiritual and second death. These are not unsaved people, but the people of the Church of Rome.
Again, in the Epistle to the Church at Ephesus, Paul entreats the saved through Grace by Faith Christians to not take part in the practices of those who suffer the wrath of God lest they sever themselves from the Kingdom of God and their salvation by sin.
But fornication, and all uncleanness, or covetousness, let it not be once named among you, as becometh saints; Neither filthiness, nor foolish talking, nor jesting, which are not convenient: but rather giving of thanks. For this ye know, that no whoremonger, nor unclean person, nor covetous man, who is an idolater, hath any inheritance in the kingdom of Christ and of God. Let no man deceive you with vain words: for because of these things cometh the wrath of God upon the children of disobedience. Be not ye therefore partakers with them. -- Eph. 5:3-7