I just showed you what Paul said about non Christians.
In the verse you referenced, Paul was talking to the Galatian Christians about the Judaizers, who were a faction of the Jewish Christians. Paul had previously brought the Gospel to the Galatian Christians, and it was warmly received by them. But the Judaizers came along and taught them a distorted Gospel. And some of these Galatian Christians were accepting of it. The distortion was the Judaizers were going to these Gentile Christians and telling them they had to also follow the law of Moses to be right with God. Nobody involved were “non-Christians.”
Pagans do what pagans do, but he most definitely called out what pagans did.
Except the Galatians were Gentile Christians, and the Judaizers were Jewish Christians.
Christ, Paul, and all the Apostles called out and told non believers they were sinners.
That’s way different than being judgemental. Jesus Himself didn’t ‘judge’ the Samaritan woman at the well for her sin.
