I think what is misunderstood is that walking in the steps of faith as Abraham did is in no way connected to the OT law. (See Romans 4:11-14 below)
Yes, Abraham believed God and his obedience confirmed that.
I am with you until here.
Abraham was declared righteous on the moment he had faith in the very covenant in where he was told in him shall all nations (gentiles included) be blessed. via his seed.
since he believed. And god declaired him righteous at that point. God, in doing so. Knew his faith was real. and through this declared him righteous.
Abraham's trust in God before and after circumcision show God's intent to make salvation available to both Jews and Gentiles on the merit of their believing God's instructions and being sealed upon obedience to same.
Abraham received circumcision as a sign, as a seal of the righteousness he had been credited with on the ground of the trust he had while he was still uncircumcised. This happened so that he could be the father of every uncircumcised person who trusts and thus has righteousness credited to him, 12 and at the same time be the father of every circumcised person who not only has had a b’rit-milah, but also follows in the footsteps of the trust which Avraham avinu had when he was still uncircumcised.
For the promise to Avraham and his seed that he would inherit the world did not come through legalism but through the righteousness that trust produces. Rom 4:11-14 CJB
Many aspects of the covenant had nothing to do with the sign of the covenant between Abraham and his people who would come (Israel) In this was the sign of the covenant. It was done not to gain eternal life. But to mark himself as a part of the covenant between God and Israel. as ONLY Israel was given this command. (although I believe a gentile who wanted to be part of this covenant were required to be circumcised also) We know in Col 2. Paul made it clear it is not the circumcision by the hand of man that made anyone clean, But the one done by the hand of God. which happens through baptism performed by God (the one who raised him from the dead)
In the NT a person trusts God's message that Jesus did in fact die as payment for the penalty of sin, was buried and resurrected. In
Yes. They would be a part of this eternal covenant given to all mankind the same way abraham did, by grace through faith
addition they trust that what God conveyed through Peter on the Day of Pentecost was in fact true. If the NT believer would repent and be water baptized in Jesus' name they would have their personal sins remitted. And God promised to fill the NT believer with the Holy Ghost. (Acts 2:38-40)
Here is where you run into problems
if we are saved by the same faith of Abraham, We are saved the way he did. We believe God and he credits to us righteousness. Paul shows this in romans 4. where he claims clearly if abraham was found by works (we know in Gal 3 circumcision was considered a work) then he had something to boast (take credit). And shares that it is the fact God does not imput sin that makes us righteous. Even david understood this. when he said blessed is the man to whom God does not impute sin (psalms 32: 1-2) And as paul tells us in rom 5 how sin was not imputed to a persons account until the law was given. Until then the only thing that condemned a person was unbelief, in which they were dead in adam, until they repented and came to faith (like Noah and Abraham and others) Of course, like he also said, once the command came, Sin revived and I died. Its like you drive down the street at 70 miles an hour. yet there is no law about a speed limit. they can not charge a man for a sin. he broke no law. Once they make a law and post the speed limit at 35. If the man drives at 70 he can be charged for a crime, and must pay his debt
The law then was given, as Paul told us in gal 3. To bring us to christ.
the moral law as God called the minister of death written on stone, is what brings us to our knees with knowledge of sin and our guilt
the sacrificial law showed us what MUST be done to be atoned or repay that debt so we could be set free or justified (redeemed) of that debt.
It is that which saved us. that is what saved Abraham as God looked forward. as the scripture says, he passed over the sins previously committed.
Abraham was not saved by Baptism in water. Since God said we would be saved as he was. We can not be saved by baptism. When you add that WORK to the gospel. you in effect teach a different gospel.
Water baptism is to the church was Circumcision was to Israel. A sign of what God does to each of us when we come to him in faith. It is not the circumcision or baptism done by the hand of man, But by the hand of God