So, salvation is by grace through faith and faith is not even from ourselves, but is a gift from God!
I believe you are referring to Ephesians 2:8 here. And if I understand that verse correctly, it is salvation that is a gift from God, not faith. Faith is from ourselves (Genesis 15:1-6, Hebrews 11:6).
"For by grace you have been saved through faith and that not of yourselves
, it is the gift of God not of works, lest anyone should boast. For we are His workmanship, created in Christ Jesus for good works, which God prepared beforehand that we should walk in them."
The phrase in question is "that not of yourselves", what does it refer to? I suppose it could refer to either salvation or faith. Salvation is a gift for sure, but is faith also a gift? It's proximity to "that not of yourselves" leans credance to the concept. And 1 Cor. 12 speaks of the "gift of faith". And faith comes from hearing the word of God; and faith is not something that we can manufacture on our own but is dependent upon God revealing His word to us. So I lean towards faith itself being a gift from God, as well as salvation, of course.
And then from experience, whenever I hear the voice of the Lord, faith comes with word. I don't have to work it up. Noah had faith to build the ark, because God told him to build the ark and revealed to him what was coming. I believe faith is a by-product of humbly receptively hearing the word of God. But then it takes faith to listen for and trust the word of God.
So faith is both something God gives us and something that we choose. But does faith originate within ourselves? I don't think so. If God doesn't turn the lights on, we stay in darkness. We are dead in our trespasses and sins and dead men cannot raise themselves from the dead; only God can give dead men life. So salvation is completely the work of God in our hearts. But then we also accept that we have free choice. Calvanism vs. Armenianism, which one?
God Foreordains -> Man is Saved -> Man Receives Salvation by Faith
God Foreknows -> Man Receives Salvation by Faith -> Man is Saved
Note how they are both linear/temporal, but God is eternal. I believe both are true simultaneously. It's like AC electricity which flows both directions at the same time. I don't know how it does that, but I know when I turn the switch on the lights come on. In like manner, faith is a gift and a response. I don't know how salvation works, but I know that I am saved because of the Sacrifice of Jesus; and God turned on the lights for me.
Thanks for reading my ramblings; I hope they are encouraging!