15 You too should be on your guard against him, because he strongly opposed our message.
15 Beware of him yourself, for he strongly opposed our message.
15 Fiercely opposed to our Message, he caused no end of trouble. God will give him what he's got coming.
15 You also must beware of him, for he has greatly resisted our words.
15 Be careful of him, for he fought against everything we said.
Matthew Henry's Commentary on 2 Timothy 4:15
Commentary on 2 Timothy 4:14-18
(Read 2 Timothy 4:14-18)
There is as much danger from false brethren, as from open enemies. It is dangerous having to do with those who would be enemies to such a man as Paul. The Christians at Rome were forward to meet him, Acts 28, but when there seemed to be a danger of suffering with him, then all forsook him. God might justly be angry with them, but he prays God to forgive them. The apostle was delivered out of the mouth of the lion, that is, of Nero, or some of his judges. If the Lord stands by us, he will strengthen us in difficulties and dangers, and his presence will more than supply every one's absence.