15:1-29 What vital foundational doctrine of the Christian faith was resolved here?

That salvation is by grace through faith alone. It is not of works, as the Jewish Christians were trying to teach (CP Eph 2:8-9).

This is a milestone in the history of Christianity. Until the question of Gentile circumcision was settled here many Jewish Christians believed that Gentile converts had to be circumcised like them and keep the law of Moses, as well as believe in Jesus, to be saved (CP Ac 15:1,5).

Peter reminded them that when God first visited the Gentiles through him some years before, the Gentiles were saved solely on the basis of their faith in Jesus, and God confirmed their salvation by baptizing them with the Holy Spirit while Peter was still preaching to them.

They were not required to be circumcised, nor meet any other requirement of the Old Testament law (CP Ac 10:34-46 and 11:17-18).

Peter then mildly reproved the Jewish Christians for trying to impose requirements of the law upon the Gentile Christians when the Jews themselves could not even conform to them (CP 15:7-11).

After Paul and Barnabas recounted the miracles God had wrought among the Gentiles through them, James summed up in the light of Old Testament prophecy now being fulfilled in the salvation of the Gentiles, that they should not be burdened with any requirements of the law. He did recommend however that they should be required to abstain from food offered to idols, to keep themselves from sexual immorality, not to eat the meat of animals that had been strangled, and not to eat blood.

These decrees were necessary so that weak Jewish Christians would not be exposed to temptation, and although they may have been Old Testament law, they are also commanded in the New Testament under grace (CP Gen 9:3-4 with Lev 17:10-11; Ro 14:13-22; 1Cor 8:4-13; 1Th 4:3-7). We should note here that Gen 9:3-4 was commanded by God long before the Levitical law. God always regarded blood as sacred, because it carries the life of the flesh.

Everyone in the Jerusalem church agreed with James' recommendations and authorized two of their leaders, Judas Barsabas and Silas, to return with Paul and Barnabas to Antioch, to report on the church's findings (CP Ac 15:13-31).

See also comments on Eph 2:8-10 and Tit 2:11 and author's studies Salvation - a Free Will Choice or Predestinated? and Chosen by God? in his book Advanced Studies in the Christian Faith (Volume 1), and The Doctrine of Grace in his book Advanced Studies in the Christian Faith (Volume 2). The rebuilding and restoration of the tabernacle of David in V15 refers to the building of the church, composed of both Jews and Gentiles.

Acts: