Easton's Bible Dictionary (1897)/Nicolaitanes
Nicolaitanes: The church at Ephesus (Revelation 2:6) is commended for hating the "deeds" of the Nicolaitanes, and the church of Pergamos is blamed for having them who hold their "doctrines" (Revelation 2:15). They were seemingly a class of professing Christians, who sought to introduce into the church a false freedom or licentiousness, thus abusing Paul's doctrine of grace (comp. 2 Peter 2:15,16,19), and were probably identical with those who held the doctrine of Balaam (which see), Revelation 2:14.