But unto you I say, and unto the rest in Thyatira, as many as have not this doctrine, and which have not known the depths of Satan, as they speak; I will put upon you none other burden. But unto you I say, and unto the rest - "But unto the rest, etc. This is the reading of the Complutensian, and seems preferable to the common one, as it evidently shows that the rest of the epistle wholly concerns the faithful, who have not received the former doctrine of error. I will put upon you none other burden is a commendation of the sound part of the Church, that they have no need of any new exhortation or charge to be given them, no new advice but to persevere as usual. See Romans 15:14, Romans 15:15. The expression of burden is taken from the history of Ahab, 2 Kings 9:25 : The Lord laid this burden on him; a word often used by the prophets to signify a prophecy threatening heavy things to be suffered. See on Isaiah 13:1 (note), and Numbers 4:19 (note)." See Dodd's Notes.
It is worthy of remark that the Gnostics called their doctrine the depths of God, and the depths of Bythos, intimating that they contained the most profound secrets of Divine wisdom. Christ here calls them the depths of Satan, being master pieces of his subtlety. Perhaps they thought them to be of God, while all the time they were deceived by the devil.