Its clear that salvation cannot be lost in the church age , but what about the Old testament ? The Old testament would be the period up to the death of Jesus?
If they cannot lose their salvation in the Old Testament then all the Jews would be saved because Israel as a nation was in the truth at one time, and their sins were covered every year by the blood of animals so how did they go astray as a nation and leave the truth and have other nations rule over them which God said would happen if they did not abide by the truth, but if they abide by the truth then no enemy can rule over them.
But God said in the Old Testament that they can go astray and lose their salvation.
Rom 11:18 Boast not against the branches. But if thou boast, thou bearest not the root, but the root thee.
Rom 11:19 Thou wilt say then, The branches were broken off, that I might be graffed in.
Rom 11:20 Well; because of unbelief they were broken off, and thou standest by faith. Be not highminded, but fear:
Rom 11:21 For if God spared not the natural branches, take heed lest he also spare not thee.
Rom 11:22 Behold therefore the goodness and severity of God: on them which fell, severity; but toward thee, goodness, if thou continue in his goodness: otherwise thou also shalt be cut off.
The New Testament saints can be cut off like the Old Testament saints that do not obey the laws of God which in the New Testament it is moral laws, laws of love, for we no longer go by the physical laws and ordinances.
Eze 18:20 The soul that sinneth, it shall die. The son shall not bear the iniquity of the father, neither shall the father bear the iniquity of the son: the righteousness of the righteous shall be upon him, and the wickedness of the wicked shall be upon him.
Eze 18:21 But if the wicked will turn from all his sins that he hath committed, and keep all my statutes, and do that which is lawful and right, he shall surely live, he shall not die.
Eze 18:22 All his transgressions that he hath committed, they shall not be mentioned unto him: in his righteousness that he hath done he shall live.
Eze 18:23 Have I any pleasure at all that the wicked should die? saith the Lord GOD: and not that he should return from his ways, and live?
Eze 18:24 But when the righteous turneth away from his righteousness, and committeth iniquity, and doeth according to all the abominations that the wicked man doeth, shall he live? All his righteousness that he hath done shall not be mentioned: in his trespass that he hath trespassed, and in his sin that he hath sinned, in them shall he die.
Eze 33:11 Say unto them, As I live, saith the Lord GOD, I have no pleasure in the death of the wicked; but that the wicked turn from his way and live: turn ye, turn ye from your evil ways; for why will ye die, O house of Israel?
Eze 33:12 Therefore, thou son of man, say unto the children of thy people, The righteousness of the righteous shall not deliver him in the day of his transgression: as for the wickedness of the wicked, he shall not fall thereby in the day that he turneth from his wickedness; neither shall the righteous be able to live for his righteousness in the day that he sinneth.
Eze 33:13 When I shall say to the righteous, that he shall surely live; if he trust to his own righteousness, and commit iniquity, all his righteousnesses shall not be remembered; but for his iniquity that he hath committed, he shall die for it.
Eze 33:14 Again, when I say unto the wicked, Thou shalt surely die; if he turn from his sin, and do that which is lawful and right;
Eze 33:15 If the wicked restore the pledge, give again that he had robbed, walk in the statutes of life, without committing iniquity; he shall surely live, he shall not die.
Eze 33:16 None of his sins that he hath committed shall be mentioned unto him: he hath done that which is lawful and right; he shall surely live.
The Old Testament could lose their salvation but if they turned back to the truth they could regain their salvation.