I read that he was justified twice, that word being used in the NT referring to Gen.15 (Rom.4) and Gen.22.(James 2)
Abrahams' faith in God's land/greatness/blessing promise to him is mentioned in Heb.11 as well, referring to Gen.12.
But Abraham is not to be said to be saved until Gen.15:6. with the belief that God would give him a seed.
One of the classic Old Testament texts on justification is Genesis 15:6. This verse, which figures prominently in Paul's discussion of justification in Romans and Galatians, states that when God gave the promise to Abraham that his descendants would be as the stars of the sky (Gen. 15:5, cf. Rom. 4:18-22) Abraham "believed God and it was reckoned to him as righteousness" (Rom. 4:3). 1This passage clearly teaches us that Abraham was justified at the time he believed the promise concerning the number of his descendants.Now, if justification is a once-for-all event, rather than a process, then that means that Abraham could not receive justification either before or after Genesis 15:6. However, Scripture indicates that he did both.
First, the book of Hebrews tells us that "By faith Abraham obeyed when he was called to set out for a place that he was to receive as an inheritance, not knowing where he was going." (Hebrews 11:8)
Every Protestant will passionately agree that the subject of Hebrews 11 is saving faith—the kind that pleases God and wins his approval (Heb. 11:2, 6)—so we know that Abraham had saving faith according to Hebrews 11.
But when did he have this faith? The passage tells us: Abraham had it "when he was called to go out to the place he would afterward receive." The problem for the once-for-all view of justification is that is that the call of Abraham to leave Haran is recorded in Genesis 12:1-4—three chapters before he is justified in 15:6. We therefore know that Abraham was justified well before (in fact, years before) he was justified in Gen. 15:6.
But if Abraham had saving faith back in Genesis 12, then he was justified back in Genesis 12. Yet Paul clearly tells us that he was also justified in Genesis 15. So justification must be more than just a once-for-all event.
But just as Abraham received justification before Genesis 15:6, he also received it afterwards, for the book of James tells us, "Was not our ancestor Abraham justified by works when he offered his son Isaac on the altar? You see that faith was active along with his works, and faith was brought to completion by the works. Thus the scripture was fulfilled that says, 'Abraham believed God, and it was reckoned to him as righteousness,' and he was called the friend of God." (James 2:21-23)
James thus tells us "[w]as not our ancestor Abraham justified ... when he offered his son Isaac on the altar?" In this instance, the faith which he had displayed in the initial promise of descendants was fulfilled in his actions (see also Heb. 11:17-19), thus bringing to fruition the statement of Genesis 15:6 that he believed God and it was reckoned to him as righteousness.
Abraham therefore received justification—that is, a fuller fruition of justification—when he offered Isaac.2 The problem for the once-for-all view is that the offering of Isaac is recorded in Gen. 22:1-18—seven chapters after Gen. 15:6. Therefore, just as Abraham was justified before 15:6 when he left Haran for the promised land, so he was also justified again when he offered Isaac after 15:6.
Therefore, we see that Abraham was justified on at least three different occasions: he was justified in Genesis 12, when he first left Haran and went to the promised land; he was justified in Genesis 15, when he believed the promise concerning his descendants; and he was justified in Genesis 22, when he offered his first promised descendant on the altar.
As a result, justification must be seen, not as a once-for-all event, but as a process which continues throughout the believer's life.