Paul did suggest the idea of eternal justification by Christ's faith in Gal 2:16.
No. It has nothing to do with our faith being a gift from God.
Eternal justification is an error of hyper-calvinism, on par with the time-lapse error of same. There are many scriptures which exposes this error, such as John 1:12, 3:18, 5:24, 10:5,27, 17:3, Rom.1:16-17, 6:17-18, 7:6, 8:5-6,14-16, 1Cor.1:30-31, 2:12-14, 4:3-6, 2Thes.2:13, 1John 4:2-3, 5:1,10, 2John v.9 etc.
Add to this the absurd consequences and implications of this error:
A. While someone was going about to establish a righteousness of his own and bringing forth dead works, evil deeds, and fruit unto death, he was yet pleasing to God.
B. Without faith it is possible to please God, and some who are in the flesh are able to please God.
C. When they were dead in trespasses and sins wherein in time past they walked according to the course of this world, according to the prince of the power of the air, the spirit that now worketh in the children of disobedience: among whom also they all had their conversation in times past in the lusts of their flesh, fulfilling the desires of the flesh and of the mind; were yet not the children of wrath, but pleasing to God. (Eph. 2:1-3).
So when does justification happen? The Bible says:
Rom.3
[28] Therefore we conclude that a man is justified by faith without the deeds of the law.
[29] Is he the God of the Jews only? is he not also of the Gentiles? Yes, of the Gentiles also:
[30] Seeing it is one God, which shall justify the circumcision by faith, and uncircumcision through faith.
Rom.5
[1] Therefore being justified by faith, we have peace with God through our Lord Jesus Christ:
[2] By whom also we have access by faith into this grace wherein we stand, and rejoice in hope of the glory of God.
Gal.3
[8] And the scripture, foreseeing that God would justify the heathen through faith, preached before the gospel unto Abraham, saying, In thee shall all nations be blessed.
[24] Wherefore the law was our schoolmaster to bring us unto Christ, that we might be justified by faith.
Justification is by faith, not by fate. This
means that faith is the instrument through which a person receives the imputed righteousness of Christ and is justified. This does
not mean however that faith is a
condition or a requirement or prerequisite to justification.