Galatians 6:11-12

See with what large letters I am writing to you with my own hand.

(v11, ESV)

Apparently, Paul was writing with large letters. There are a few reasons why he emphasizes this point. One possibility is that Paul had a seeing problem or maybe he had an eye disease. Paul may simply be emphasizing the importance of his letter or this specific section. Regardless, he is making a point to his readers.

It is those who want to make a good showing in the flesh who would force you to be circumcised, and only in order that they may not be persecuted for the cross of Christ.

(v12, ESV)

Paul once again revisits this issue of circumcision. He is not saying that circumcision is wrong, but teaching that circumcision is necessary for salvation is wrong. Teaching this would mean that it is by works that we are saved. Nothing could be further from the truth. It is by grace through faith in Jesus that we are saved.

With regards to those who are teaching circumcision as a requirement for salvation, they are doing it to look good. They want to make a good showing in the flesh, which brings us back to the contrast between living by the Spirit and living by the flesh. These false teachers are living by the flesh and gratifying the desires of the flesh. Don't listen to them; they do not live by the Spirit.

Paul answers one question that we all may have. Why do they do this? Why do these false teachers teach this lie? They teach circumcision because they fear persecution.

But if I, brothers, still preach circumcision, why am I still being persecuted? In that case, the offense of the cross has been removed.

(Galatians 5:11, ESV)

If your teaching is opposed to circumcision, you will be persecuted. Circumcision was highly promoted by the Jewish non-Christians as well as the Jewish Christians. Preaching circumcision is in line with their thinking, so they wouldn't have any reason to be opposed to circumcision. However, preaching against circumcision is contrary to the way they were probably raised and taught. However, preaching circumcision is contrary to the cross of Christ.