Luke
Acts 15:2BSB·traditional attribution

And after engaging these men in sharp debate, Paul and Barnabas were appointed, along with some other believers, to go up to Jerusalem to see the apostles and elders about this question.

John Calvin Reformed @genevareformer

2. When there was sedition arisen. This was no small trial, in that Paul and Barnabas are haled into a troublesome tumult. There was mischief enough already in the matter [dissension] itself; but it is a more cruel mischief when the contention waxeth so hot, that they are enforced to fight with their brethren as with enemies.

Matthew Henry Presbyterian @wholebiblehenry

Even when things go on very smoothly and pleasantly in a state or in a church, it is folly to be secure, and to think the mountain stands strong and cannot be moved; some uneasiness or other will arise, which is not foreseen, cannot be prevented, but must be prepared for.

Commenting on Acts 15:1-5

John Gill Reformed Baptist @doctorgill

When therefore Paul and Barnabas,.... Who were the ministers of the uncircumcision, and were just returned from preaching the Gospel among the Gentiles, with success, and were advocates for them, being witnesses of the grace that was bestowed on them, and therefore opposed the sentiments of these men: and had no small dissension and disputation with them; which was attended with much heat and sharpness...