Matt Black said:
Oh, where to start? The fact that the first Christians were Jewish converts (Acts 2);
"The first Jewish converts?"
I was circumcised; they were circumcised. It has nothing to do with Christianity. It is a personal preference. Christians before this generation have been carrying on this practice for ages. It has nothing to do with religion. My parents aren't even saved and thought it a wise thing to do. It has nothing to do with Christianity.
Having a Jewish background would lead them to believe it would be the right thing to do; not that it would be connected to salvation. Would circumcision harm them? No. Was it connected to salvation? No. Only in the minds of a heretical sect that was condemned by Paul was it connected to salvation. Concerning them Paul said: "Let them be accursed."
the fact that Peter had to be convinced by God that the Gentiles were not unclean (Acts 10:11-16; 28);
This is not directly related to circumcision; only indirectly. The Jewish mentality was that they were God's chosen people, and all others were unclean. Thus the Jews felt unclean to enter the house of any Gentile. Consequently God gave Peter a vision to inform him not to call any person unclean. The question was not circumcision, but not to treat the Gentiles as "unclean."
the astonishment and in some cases initial opposition to this from the rest of the Jerusalem congregation (Acts 11:1-3; 18); and the continuing disagreements settled by the Council of Jerusalem in Acts 15.
Have you never read the context of Acts 15?
Acts 15:1 And certain men which came down from Judaea taught the brethren, and said, Except ye be circumcised after the manner of Moses, ye cannot be saved.
--These men were unsaved. They believed in a salvation of works. They troubled Paul wherever he went. Paul writes of them extensively in the Book of Galatians.
Acts 15:3 And being brought on their way by the church, they passed through Phenice and Samaria, declaring the conversion of the Gentiles: and they caused great joy unto all the brethren.
--Paul and Barnabas had just been on a long missionary journey where many souls were saved, baptized, and many churches established. Most of them were Gentiles. None of them were circumcised. That was not the practice of Paul. And he gave testimony to that fact.
Acts 15:5 But there rose up certain of the sect of the Pharisees which believed, saying, That it was needful to circumcise them, and to command them to keep the law of Moses.
--The Pharisees had to get their two cents worth. But they were Pharisees not Christians. Note that Paul did not call himself a Pharisee any longer. Only an unsaved Pharisee would put such a yoke on newly saved Christians so that they might try and stamp the movement out. Christianity was not Judaism, and these heretics couldn't make it so.
James was the pastor of the church. Here is what James said:
Acts 15:13 And after they had held their peace, James answered, saying, Men and brethren, hearken unto me:
Acts 15:19-20 Wherefore my sentence is, that we trouble not them, which from among the Gentiles are turned to God: But that we write unto them, that they abstain from pollutions of idols, and from fornication, and from things strangled, and from blood.
The heretical Judaizers had once and for all lost their case. It was never a case to begin with. They had been causing trouble. Now that trouble could be published abroad and the public could know that it was a heresy denounced by all the disciples, with one accord.
Note, that with Paul it was never an issue. He never attached salvation with circumcision, and neither did any other apostle. You won't find it in Scripture among believers.