A common thorn in the side of most Calvinists is Ephesians 2:8 which reads
For by grace you have been saved through faith. And this is not your own doing; it is the gift of God,
To keep with the reformed doctrine of irresistible grace (ie. men being robots) they prefer to make the case that faith is included in the gift given from God.
The problem with your interpretation is that if faith is included in what is gifted to us then it makes the through (διὰ) superfluous and unnecessary given the context.
Rather, πίστεως (faith) is the conduit διὰ (through) which χάριτί (grace) is actualized.
Word for word it is: τῇ The γὰρ for/reason χάριτί grace ἐστέ you σεσῳσμένοι are saved διὰ through πίστεως faith καὶ and τοῦτο this οὐκ not ἐξ out of ὑμῶν of yours θεοῦ God τὸ the δῶρον gift/sacrifice/offering.
Further, Robertson’s Word Pictures puts it this way:
Neuter, not feminine ταυτη, and so refers not to πιστις (feminine) or to χαρις (feminine also), but to the act of being saved by grace conditioned on faith on our part. Paul shows that salvation does not have its source (εξ υμων, out of you) in men, but from God. Besides, it is God’s gift (δωρον) and not the result of our work. (emphasis mine)
For more context, this verse is almost the same as verse 5 before it but with the addition of “through faith”. Verse 5 reads:
even when we were dead in our trespasses, made us alive together with Christ—by grace you have been saved—
If faith is part of the gift and is indeed necessary for salvation, why was it omitted in verse 5?