From Hebrew 11:8-19 we have Abrahams walk of faith that showed that he had believed what God said (Gen.15:6)
It was his faith that resulted in his salvation and that faith revealed itself by its obedience.
That is made clear by Paul in Rom.4 where Paul states that Abraham was not saved by any works, but by his faith and to be children of Abraham, the father of faith, we must do likewise.
Is it surprising that so few Protestant commentaries address Genesis 12 and the subject of justification, although Paul uses the very same language to describe BOTH Genesis 12 and 15? You are placing artificial definitions upon what Scripture describes as similar events.
Gen.12 shows the Convenant that God made with Abraham.
Gen. 15:6 shows the faith that Abrhaham had in what God said about that Covenant and that was imputed to him for righteousness and Gen.15:6 is what Paul is referring to.
'therefore it is of faith, that it might be by grace (Rom.4:16)
And there you have it. One's faith shown by their works. Without works of love, you have dead faith, worthless for salvation. Without faith, you cannot be pleasing to God. Really, you haven't shown how we are saved by faith alone, and James quite clearly says we are not saved by faith alone.
end of story.
Regards