According to Heb 11:8,
Hebrews 11:8 King James Version (KJV)
8 By faith Abraham, when he was called to go out into a place which he should after receive for an inheritance, obeyed; and he went out, not knowing whither he went.
Abraham came to faith in Gen 12:1-4,
but according to Romans 4:3 he was not justified until Gen 15:6.
Romans 4:3King James Version (KJV)
3 For what saith the scripture? Abraham believed God, and it was counted unto him for righteousness.
And according to James 2:24, Abraham is further justified in Gen 22:1-18.
James 2:20-22King James Version (KJV)
20 But wilt thou know, O vain man, that faith without works is dead? 21 Was not Abraham our father justified by works, when he had offered Isaac his son upon the altar? 22 Seest thou how faith wrought with his works, and by works was faith made perfect?
So, it took a long time for Abraham to be justified.
But Scripture also says:
2 Corinthians 4:16 King James Version (KJV)
16 For which cause we faint not; but though our outward man perish, yet the inward man is renewed day by day.
St. Paul says we are justified (i.e. renewed) day by day. That sounds like a long process. One that lasts a life time.
1 Samuel 13:14 King James Version (KJV)
14 But now thy kingdom shall not continue: the Lord hath sought him a man after his own heart, and the Lord hath commanded him to be captain over his people, because thou hast not kept that which the Lord commanded thee.
1 Samuel 16:13King James Version (KJV)
13 Then Samuel took the horn of oil, and anointed him in the midst of his brethren: and the Spirit of the Lord came upon David from that day forward. So Samuel rose up, and went to Ramah.
God justifies David twice in 1 Samuel.
2 Samuel 12:7-13 King James Version (KJV)
7 And Nathan said to David, Thou art the man. Thus saith the Lord God of Israel, I anointed thee king over Israel, and I delivered thee out of the hand of Saul; 8 And I gave thee thy master’s house, and thy master’s wives into thy bosom, and gave thee the house of Israel and of Judah; and if that had been too little, I would moreover have given unto thee such and such things. 9 Wherefore hast thou despised the commandment of the Lord, to do evil in his sight? thou hast killed Uriah the Hittite with the sword, and hast taken his wife to be thy wife, and hast slain him with the sword of the children of Ammon.10 Now therefore the sword shall never depart from thine house; because thou hast despised me, and hast taken the wife of Uriah the Hittite to be thy wife. 11 Thus saith the Lord, Behold, I will raise up evil against thee out of thine own house, and I will take thy wives before thine eyes, and give them unto thy neighbour, and he shall lie with thy wives in the sight of this sun. 12 For thou didst it secretly: but I will do this thing before all Israel, and before the sun.
13 And David said unto Nathan, I have sinned against the Lord. And Nathan said unto David, The Lord also hath put away thy sin; thou shalt not die.
Then he loses his justification when he sins by adultery with Bathsheba and murder of Uriah, then begs forgiveness and gets it back.
In the New Testament, all the Apostles and disciples were justified by Jesus Christ and then they fell away when He was arrested by the Jews. Then they came back when He rose again from the dead.
Yeah, it sounds to me like justification is a process. A lifetime process.