Now I urge you, brothers, watch out for those who are causing divisions and occasions for falling [away from God over matters] contrary to the teaching you have learned, and withdraw from them [i.e., stop listening to their false teaching].
For it is to be expected [i.e., it is inevitable] that there would be dissensions among you, so that those who are approved [by God] can become known among you.
I told you the last time I was there, and now before returning, I [again] warn those who have sinned in the past as well as the rest, that if I come again I will not spare you [i.e., I will rebuke and discipline you],
And if any person does not obey our instructions, [given] in this letter, you should take note of him so that you do not associate with him, in hope that he will become ashamed [of his conduct].
Now we command you, brothers, in the name [i.e., by the authority] of our Lord Jesus Christ, that you people stay away from every brother [or sister] who lives an idle life [See note on I Thess. 5:14], and not according to the [inspired] tradition which you received from us.
But just as there were false prophets among the people before, there will also be false teachers among you [Christians]. They will privately teach harmful doctrines that destroy people [spiritually], by even denying [that Jesus is] the Master, [and thereby] destroying themselves quickly.
If anyone comes to you [i.e., to your meetings] who does not bring this teaching [about Christ], you should not welcome him into your home or give him [any] greetings [i.e., suggesting approval or endorsement].