Abraham believed God, and it was counted (i.e. that Abraham believed God was accounted/accredited) unto him (i.e. unto Abraham) for righteousness.
Read this verse- that Abraham's faith was reckoned to him by God - that "faith was reckoned to Abraham for righteousness"?
[Rom 4:9 KJV] 9 [Cometh] this blessedness then upon the circumcision [only], or upon the uncircumcision also? for we say that
faith was reckoned to Abraham for righteousness.
5¶But to him that worketh not, but believeth on him that justifieth the ungodly (i.e. to him that worketh not but believeth on God: to Abraham), his faith (i.e. the faith of the one who worketh not but believeth on God: Abraham's faith) is accounted/accredited for righteousness.
The "his faith" is Christ's faith which is accounted for righteousness, as Rom 4:9 so inform us, because if reckoned, it couldn't have been Abraham's faith. Only Christ's faith is righteous/has righteousness. That is why I included the verses I did - to demonstrate that fact. Here I post again:
[Rom 3:22 KJV]
22 Even
the righteousness of God [which is] by faith of Jesus Christ unto all and upon all them that believe: for there is no difference:
[Rom 10:3 KJV]
3 For they being ignorant of
God's righteousness, and going about to establish their own righteousness,
have not submitted themselves unto the righteousness of God.
[Rev 2:13 KJV]
13 I know thy works, and where thou dwellest, [even] where Satan's seat [is]: and thou holdest fast my name, and
hast not denied my faith, even in those days wherein Antipas [was] my faithful martyr, who was slain among you, where Satan dwelleth.
[Phl
3:9 KJV] 9 And be found in him,
not having mine own righteousness, which is of the law, but that which is through the faith of Christ, the righteousness which is of God by faith:
Could it have been made any clearer by God than that? That righteousness only comes through the faith of Christ imputed to man by God, and that man cannot produce that of himself? To have the one, you have to also must have the other. There simply is no other possibility.
According to vv 3 and 5, it is Abraham who is doing the believing, not God. So the "his faith" must be Abraham's faith, because he is the only one being spoken of in this context as "believing". And it iis therefore Abraham's faith that is accounted to Abraham as righteousness by God; not God's faith being accredited as righteousness to God by Abraham.
I didn't say that God does the believing. I said that Abrahm's belief came from Christ's imputed faith and Abraham realized that was where his belief came from, as all of the saved realize. It became Abraham's because God gave it to him through His grace. It was Christ's faith being accredited to Abrham that gave Abraham Christ's righteousness. Christ was the only one truly faithful, and that faith alone, not man's, pleased the Father. That is why/how righteousness was accounted to Abraham, and that is how/why Christ is the Saviour and man is not.
[Rom 1:16-17 KJV]
16 For I am not ashamed of the gospel of Christ: for it is the power of God unto salvation to every one
that believeth; to the Jew first, and also to the Greek.
17
For therein is the righteousness of God revealed from faith to faith: as it is written, The just shall live by faith.
[Heb 3:1-2 KJV]
1 Wherefore, holy brethren, partakers of the heavenly calling, consider the Apostle and High Priest of our profession,
Christ Jesus;
2
Who was faithful to him that appointed him, as also Moses [was faithful] in all his house.
BTW after pondering John 6, I continue to disagree with your assessment of it. I believe that it is saying it is the work of God
that one believes.