The Greek preposition "ek" means out of or out from, and points to the origin of something. Out from faith refers to something based on faith, or more explicitly, based on God crediting our faith as righteousness. And what is that something? Salvation by being transferred into Christ where we undergo the washing of regeneration, rebirth as a new creation, and are then indwelt with the Holy Spirit. Thus all the blessings of salvation including justification can be said to be "based on faith.!"
Romans 1:17, "...But the righteous one will live
based on faith." I think walking according to our (credited) faith is in view here rather than salvation's blessings.
Romans 3:30, "since indeed God who will justify the circumcised
based on faith and the uncircumcised through faith is one." Here I think the idea is New Covenant faith arises from Old Covenant faith for Jews, and arises without prior faith in God for Gentiles.
Romans 4:16, "For this reason
[the promises to Abraham's heirs] is
based on faith, in order that
it may be in accordance with grace, so that the promise will be guaranteed to all the descendants, not only to those who are of the Law, but also to those who are of the faith of Abraham, who is the father of us all,
Romans 5:1, "Therefore, having been
justified based on God crediting our faith as righteousness, we have peace with God through our Lord Jesus Christ,
Romans 9:30, "What shall we say then? That Gentiles, who did not pursue righteousness, attained righteousness, moreover the righteousness that is
based on God crediting their faith as righteousness.
Romans 9:32, "Why? Because
they did not
pursue it based on faith, but as though
they could by works. They stumbled over the stumbling stone,
Galatians 3:22
But the Scripture has shut up everyone under sin, so that the promise
based on God crediting our faith in Jesus Christ as righteousness might be given to those who believe.
Galatians 2:16
nevertheless knowing that a man is not justified based on the works of the Law but by means of Christ Jesus's faithfulness, even we have believed into Christ Jesus, so that we may be
justified based on the faithfulness of Christ and not based on the works of the Law; since by the works of the Law no person will be justified.
Galatians 3:8
The Scripture, foreseeing that God would justify the Gentiles
based on God crediting their faith as righteousness, preached the gospel beforehand to Abraham,
saying, “ALL THE NATIONS WILL BE BLESSED IN YOU.”
Galatians
3:24
Therefore the Law has become our tutor to lead us to Christ, so that we may be justified based on God crediting our faith as righteousness.
Galatians 5:5
For we through the Spirit,
based on God crediting our faith,as righteousness, are waiting for the hope of righteousness.
The opening conjunction (gar translated as "for") might better be translated as "The fact is," we through the Spirit....
Now I think the idea of through the Spirit refers to being indwelt. Those who are indwelt are the "we" of the verse. Then we get "out of faith" which is best translated based on God crediting our faith as righteousness, are expectantly waiting for the hope of our righteousness at the second coming of our Lord.
Romans 10:6
But the righteousness that is
based on faith says: "
Do not say in your heart, '
Who will ascend into heaven?'" (that is, to bring Christ down)
Justification is accomplished by the washing of regeneration (being made alive together with Christ) based on God crediting our worthless faith as righteousness and transferring us into Christ spiritually.
The washing of regeneration accomplishes the "circumcision of Christ" where the consequence of our sinful state and our past, present and future sins, are removed, taken out of the way and nailed on the cross so to speak, due to the faithfulness of Christ's sacrifice on the cross.