2 John 1:7

for many deceivers are entered into the world, who do not confess Jesus Christ did come in the flesh. This is the deceiver, and the antichrist.

2 John 1:9-10

Whoever transgresses, and does not abide in the doctrine of Christ, has not God: he who abides in the doctrine of Christ, has both the Father and the Son.

Revelation 2:1-2

By the messenger of the congregation in Ephesus, write: These things, says he who holds the seven stars in his right hand, who walks in the midst of the seven golden lamps:

Revelation 2:14

Nevertheless, I have a few things against you, that you have there, them who hold the doctrine of Balaam, who taught Balak to cast a stumbling block before the children of Israel, to eat things sacrificed to idols, and to commit fornication.

Revelation 2:20

Nevertheless, I have against you, that you permit that woman Jezebel, who says that she is a prophetess, to teach and to seduce my servants to commit fornication, and to eat things sacrificed to idols.

Treasury of Scripture Knowledge

Summary

As I besought thee to abide still at Ephesus, when I went into Macedonia, that thou mightest charge some that they teach no other doctrine,

Bible References

Charge

2 John 1:7
for many deceivers are entered into the world, who do not confess Jesus Christ did come in the flesh. This is the deceiver, and the antichrist.
Revelation 2:1
By the messenger of the congregation in Ephesus, write: These things, says he who holds the seven stars in his right hand, who walks in the midst of the seven golden lamps: