John Gills Exposition of the Bible Commentary - Acts 15:1
And certain men which came down from Judea ,.... To Antioch; they were not sent by the apostles, they came down of "themselves"; who they were, is not certain; that they were "judaizing" Christians, and teachers among them, is plain from the following account: according to Epiphanius F7 Contra Haeres. l. 1. Haeres. 28. they were Cerinthus, and some of his followers: these taught the brethren ; the Gentile converts at Antioch, who are styled "brethren", though they were Gentiles,... read more
William Barclay's Daily Study Bible - Acts 15:36-41
15:36-41 Some time after, Paul said to Barnabas, "Come now, let us go back and visit the brethren in every city in which we preached the word of the Lord, so that we may see how things are going with them." Barnabas wished to take John who was called Mark along with them; but Paul did not think it right to take with them one who had deserted them in Pamphylia and had not gone with them to the work. There was so sharp a difference of opinion that they were separated from each other and... read more