I agree, if someone has a moment of weakness or "relapses" it doesn't make their salvation void. We just have to repent and try again.
And we need to remember that God is very patient with us.
Mat 18:21 Then came Peter to him, and said, Lord, how oft shall my brother sin against me, and I forgive him? till seven times?
Mat 18:22 Jesus saith unto him, I say not unto thee, Until seven times: but, Until seventy times seven.
What you are talking about is oft misunderstood.
God counts us righteous by our faith (Rom 4:11-12) but the faith that counts is a true genuine faith that works by love (Gal 5:6) that fulfills the righteous requirements (Rom 8:4) of the law because the law has been established in the heart (Rom 3:31). In other words the heart has been purified by faith (Act 15:9).
A person who willfully transgresses the light of their conscience, that is, they KNOW what is the right thing to do and they willfully choose to do wrong, that person is not right with God.
Thus it is error to say that someone can be "saved" and then "slip" into an act of fornication and not "lose their salvation."
Salvation is not some sort of ticket, it is a state of being. Salvation is being saved from the corrupting influence of sin and being able to walk in the light. The purging of our past sins and being reconciled to God go alongside salvation too.
An error in modern theology is that people view salvation as some sort of "arrangement" or a "deal" that they have made with God. As long as they "believe" in something then they have made this deal and have thus entered into some sort of contract.
This error is mainly due in regards to how the death of Christ on the cross is viewed. The predominant teaching today is the "Penal Substitution" view.
The Penal Substitution view is only about 400 years old and was never taught in the early church.
The early church held to what is known as the "Ransom Model." Under the Ransom Model Jesus purchased the sinner by paying a ransom with His blood from the corrupting influence of sin. The sinner, in order to partake in the reconciliation process, would have to repent and enter into the New Covenant by faith.
It was through repentance that the mind was changed was brought into alignment with God. This in turn produced a total forsaking of all known sin because the new believer would be walking in submission to the light revealed to them. The rebellion in the heart had been broken.
Faith was the dynamic which allowed all this to happen because it is the mind totally persuaded about the things of God, thus faith is the substance and evidence of things not yet seen. A true faith is such a persuasion of the mind that an individual acts upon it in all that they do.
Thus God leads with His grace which is his influence on the heart provided as a gift and faith reacts by applying what it teaches.
This is how the early church taught it. It is not taught like that today.
Under the Penal Substitution model Jesus is the sinners substitute. Jesus takes their place on the cross and is punished by God in their stead. Thus the "penalty" of sin has been completely paid for and cannot be required again. This is where the doctrine of "eternal security" comes from because it is an inevitable logical conclusion to the Penal model.
Under the reformed school of thought they also teach that the actual "righteousness of Christ," or in other words, Jesus obedient track record, is actually transferred to the sinners account. This is known as a double imputation because the sin is transferred to Jesus and His righteousness is transferred to the sinner. Thus when God looks at the sinner "who believes" all he sees is the righteousness of Jesus Christ.
It is pure fiction and is not in the Bible. The primary verses used to support this error are 2Cor5:21 which is better understood as a "sin offering" and Rom 3:24 which is taken out of context.
This is why in the church system the "sinners prayer" is used. The "sinners prayer" which is built upon isolating several scriptures in Romans is the method by which people make this "deal" or "transaction" with God. Upon making the transaction they believe they have been "covered" by the blood because Jesus "paid the price" for them.
It is all a masterful satanic deception which sounds right and will fool those who do not actually dig deep into the Scripture. It is extremely dangerous and it is pretty much universally preached everywhere today.
The holiness side of the church (Arminian, Wesleyian, Nazarene, some Pentecostal denominations) does not place as much emphasis on the "imputed righteousness of Christ but more on what they call "total sanctification" which to put it simple is "sinning less and less."
The Arminian side of the church is much more contradictory because they use the cover of Penal Substitution to make up the slack until entire sanctification is reached.
They are really teaching the same error as that on the reformed side because both the reformers and the arminians are estabished on the premise of an inborn sin nature. Thus they have to tailor the Gospel to support a "saved in sins" message. Logically, if you are saved in your sins then there can be no sin that can disqualify you.
We have emailed many pastors to discuss these things and they all, without exception, believe that salvation is a cover and not a cleansing. Many will appear to be telling the truth until their theology is unwrapped through probing them in regards to when any sin MUST stop. None will say that any sin MUST stop.
It is because of these deceptions that no-one is coming out of their sins in the church system. Everyone gets saved "in" their sins, or they thing they do.
I really hope you ponder these things and start digging because the deception in force today is so deep and dangerous and only those who are diligent will not be fooled.
Many will say Lord, Lord and will be rejected because they bought into a false gospel message which did not have them departing from iniquity to do the Father's will.
God bless.