Yes.
God made an everlasting agreement with Abraham that required all his male descendants to be circumcised, as well as any other males who lived with them.
God doesn’t just want babies to be circumcised. Even if you’re 99 years old, you should still get circumcised. That’s what Abraham did, and he always did what God wanted him to do. God also once had Joshua circumcise all the Israelite men, all at once.
Jesus thinks circumcision laws are so important that they override Sabbath laws. In addition to mandating the circumcision of Israelite boys, God’s law says even a Gentile man can only celebrate God’s holy days if he and every male he lives with are circumcised. The Bible also says if you’re not circumcised, you can’t marry a daughter of Israel. That would be a disgrace.
Even if God’s chosen nation and other nations do practice circumcision, God isn’t satisfied. He thinks they’re not circumcised enough.
The apostles were troubled when they heard rumors that Paul was teaching Jews to give up circumcision, so they suggested a way Paul could try to disprove those rumors. Paul agreed to do so, because he actually thought circumcision was a valuable thing.
No.
Paul says he used to think it was good to be circumcised, but now he considers it a loss. He calls people who practice circumcision evildoers and mutilators of the flesh.
He even says circumcised people can’t be saved! If you’re circumcised, you’re trying to be justified by the law. To actually be justified that way, you would have to follow all of God’s laws perfectly, but no one can actually do that. So if you get circumcised, all you’re really doing is rejecting God’s gift of forgiveness. You’re alienating yourself from Jesus, who will therefore be of no value to you at all.
Only if they’re Jewish.
After some discussion, the apostles decided that Gentile Christians should not have to be circumcised. They could be saved just fine without doing that.
It doesn’t matter.
There are also passages in the Bible that say it really doesn’t matter at all whether you’re circumcised or not. These passages don’t resolve the contradiction; they only further contradict all the parts that say it’s important to be circumcised, and the parts that say it’s important not to be circumcised.
Paul says as long as you follow God’s law, it’s the same as if you were circumcised, even if you’re not. (In fact, uncircumcised people who obey the law are better than circumcised people who don’t.) He says an uncircumcised man who becomes a Christian should not become circumcised, or vice versa, because circumcision status is not what matters. Obeying God’s laws it what matters.
Or maybe all that matters is faith. Paul says neither circumcision nor uncircumcision has any value or meaning; all that counts is faith. Circumcision versus uncircumcision is not a thing, as far as Paul is concerned. He says God will justify both circumcised and uncircumcised people through faith. Paul says God considered Abraham righteous because of his faith, even before he was circumcised. So it’s possible to be righteous regardless of whether you’re circumcised or not.
Paul may have once taught that circumcision was important, but he had renounced it years (if not decades) before the apostles got him to demonstrate his alleged support for circumcision. Paul didn’t require his Gentile travel companions to be circumcised, because he strongly believed that circumcision didn’t matter. He characterized people who disagreed as false believers who hated freedom.