NKJV - 8 By faith Abraham obeyed when he was called to go out to the place which he would receive as an inheritance. And he went out, not knowing where he was going.
For follow-up discussion and general commentary on the topic. Comments are sorted chronologically.
► Let us study how did Abraham has so much faith of obedience:
1. When he was a Gentile idolater, Abraham was called to go into a new life and a new land (Gen. 12:1-4).
2. Promised the new land (Gen. 15:18).
3. Obeyed, not knowing whither he went.
4. Sojourned in the promised land with Isaac and Jacob (Heb. 11:9). Jacob was 15 years old when Abraham died.
5. Dwelled in tents with his heirs.
6. Looked for a permanent dwelling--a city in heaven and is called The new Jerusalem, the capital city of God over the universe (Heb. 11:10,13-16; 12:22-23; 13:14; Rev. 3:12; 21:1--Rev. 22:5).
7. In Rom. 4:1-3, Paul shows how Abraham and David were justified, after proving in Rom. 3:21-31 that both Jews and Gentiles could only be saved by grace through faith.
8. Jews claimed Abraham as their father (Rom. 9:5; Lk. 1:73; Jn. 8:39; Acts 7:2). He is the father of the Jewish nation, was a heathen, an uncircumcised Gentile, before God pardoned him by grace through faith. He could not have been justified by obedience to the law, which was not until 430 years later (Gal. 3:17). Paul points out that Abraham was pardoned the same way the gospel saves Jews and Gentiles. Why should the Jews condemn Christianity and oppose Gentiles when they were included in the Abrahamic covenant (Gen. 12:1-3; 17:4)?
9. Paul also proves that this blessing did not come through circumcision, for Abraham had it many years before he was circumcised (Rom. 4:9-12 Gen. 12:1-3; 15:6; 17:1-14). If Abraham was blessed before and without circumcision, then Gentiles also could be.
10. Abraham believed God, and it was counted unto him for righteousness. Rom 4:3
11. If Abraham worked for and merited justification, then it was not of grace because God owed it to him. But if he believed God for it instead of working for it, then faith was counted for righteousness and God gave it to him as a favour. Since he was called when he was a Gentile idolater and he was justified freely by faith, then all other sinners can likewise be justified (Rom. 3:21-28; 5:1-11).
12. Abraham was redeemed by faith, the same as all other redeemed ones (Gen. 15:6; Rom. 4).
13. It is clear from Gen. 22 that Abraham proved his faith in God when he was asked to offer up Isaac as a sacrifice. It was faith that led him to this act of obedience (v. 23). Had he refused to obey, it would have demonstrated that he had no faith in God or His Word. It is also clear that this act of faith and works was not his initial justification by faith. That was at least 40 to 50 years before offering Isaac (Gen. 12:1-4; 15:6; Rom. 4:1-6).
14. Abraham was called the Friend of God! What a blessing! (Jas 2:23)
Hope these clarify!
Shalom, Selva Moses