If faith is the evidence of things not seen, and you can't see faith, then how do you know whether faith or salvation came first?
If God says, "I will... do such and such" and He presents it in the form of a promise (i.e. future form), and all there is to do is to believe it...even if you can't 'do' it yourself...
Because the Bible makes that clear - that the Holy Spirit indwells only those whom God saves and makes born again, from which, are they given faith as a gift: salvation first, from salvation, faith, from faith, belief. Given that God made a promise (which He did make), then as it is His promise, He therefore alone took upon Himself sole responsibility to bring it all completely to fruition, otherwise, the promise could not be guaranteed, and hence, God could not make it, but it was made by Him. IOW, for it to come true, God had to make Himself guarantor of His own promise - its fulfillment not being dependent upon anything outside of Himself, who would make it all transpire. Consequently, a person's belief, if true belief, had also to be included as part of His promise, because were the giving of belief not part of the promise, yet it still being a requirement to receive the promise, then God could not rightfully have made the promise because things outside of God's control could and would have, invalidate it - notice in Rom 9:8, the "children of the promise" part - that of the promise itself, only certain specific spiritual children are brought forth. As such, they all, and they alone, must come to belief. Should any not, or should it not be of them alone. then the promise becomes of no effect because it would be broken, which would be impossible.
[Rom 9:8 KJV]
8 That is, They which are the children of the flesh, these [are]
not the children of God: but the children of the promise are counted for the seed.
[Gal 2:16 KJV]
16 Knowing that a man is not justified by the works of the law,
but by the faith of Jesus Christ, even we have believed in Jesus Christ, that we might be justified by the faith of Christ, and not by the works of the law: for by the works of the law shall no flesh be justified.
[Heb 6:17 KJV]
17 Wherein
God, willing more abundantly to shew unto the heirs of promise the immutability of his counsel, confirmed [it] by an oath:
[1Pe 1:3-4 KJV]
3 Blessed [be] the God and Father of our Lord Jesus Christ, which
according to his abundant mercy hath begotten us again unto a lively hope by the resurrection of Jesus Christ from the dead,
4
To an inheritance incorruptible, and undefiled, and that fadeth not away,
reserved in heaven for you,
[Gal 5:22 KJV]
22
But the fruit of the Spirit is love, joy, peace, longsuffering, gentleness, goodness,
faith,
[Rom 8:9, 14 KJV]
9 But ye are not in the flesh, but in the Spirit, if so be that the Spirit of God dwell in you.
Now if any man have not the Spirit of Christ, he is none of his. ...
14
For as many as are led by the Spirit of God, they are the sons of God.
[1Co 3:16 KJV]
16 Know ye not that
ye are the temple of God, and [that] the Spirit of God dwelleth in you?