Ephesians 2:5 "by grace you have been saved", after explaining the beginning of our salvation or from sinner to saint. It happened by grace, after God had mercy on us, this is the context of verses 4-21, focusing in on 4-7. With verse 8 explaining all of it, from sinner to glorified bodies and eternality with the Father, Son and Holy Spirit.
Verse 8, "For by grace you have been saved through faith" Here Paul adds "for" after explaining the full completion of our salvation, from sinners to born again saints to glorified bodies, which God already see us there. He begins the sentence with "for" or because. He's going to bring a fuller explanation of our saving grace and how it gets us to those glorified bodies. The word "through" or "continuing in time toward completion". If "through" meant "by means of" it would then mean that our grace was brought about by our faith. Faith isn't how we receive grace, grace is God's unmerited favor, His gift, if you have to do anything for a gift it is no longer a gift, it's a payment or compensation for the act or deed.
Paul clarifies this with, "Not of ourself, not of works; it's a gift of God, not the result of works, so that no one may boast. Where the misunderstanding comes is with the word "boast" people have changed the meaning of the word 'boast" to mean bragging, I have do, I can, talking with excessive pride and self-satisfaction, which it can mean. But here what is trying to express a possession, of yourself, it's as simple as saying it's your faith over God's grace that saves you. Think about it, you are wanting to take credit for something God has done for you. What is your reaction to someone saying, God chose you, it's because of God's electing love that you are saved. Does that stir up something inside of you that make you have to defined that it's our faith that saved you or that brings God's grace?
This is something I had to deal with because I would think how dumb are these/this people/person that they don't know that it's faith that brings God's grace. All the time saying that God's grace is, God's unmerited favor, but my actions and thoughts did not agree with what was defending.
Not trying to get into a heated discussion or argue over this, I will better explain myself if someone would like, but I will not argue or fight over this.
What you've explained here is grace not faith, faith is our response to grace, God's unmerited favor. Look at what immediately follows the word, "faith", not of ourself, because God initiated it by causing us to be born again. I Peter 1:3 “Blessed be the God and Father of our Lord Jesus Christ! According to his great mercy, he has caused us to be born again to a living hope through the resurrection of Jesus Christ from the dead,”