Summary.  This text is not about abstaining from apparent evil.  It is, rather, simply saying: ‘Abstain from every kind of evil’;  ‘abstain from evil at all times’).

1 Thess 5:22 in the NET version reads: ‘Stay away from every form of evil.’

The AV reads: ‘Abstain from all appearance of evil’.  Without a doubt, the translators meant what the NET, NIV and other modern translations say.  But I have heard members of a previous generation of evangelical Christians, brought up on the AV, take it to mean: ‘Don’t do things that are really evil, or even things that appear to be evil.’  They thought thereby that they could prevent the gospel from being brought into disrepute.

This reading is reflected in some of the older commentaries.  Albert Barnes, for instance:

‘[Abstain] not only from evil itself, but from that which seems to be wrong. There are many things which are known to be wrong. They are positively forbidden by the laws of heaven. . . . But there are also many things about which there may be some reasonable doubt. . . . There are many things which, in themselves, may not appear to us to be positively wrong, but which are so considered by large and respectable portions of the community; and for us to do them would be regarded as inconsistent and improper.

‘There are things, also, where, whatever may be our motive, we may be certain that our conduct will be regarded as improper. A great variety of subjects, such as those pertaining to dress, amusements, . . . and various practices in the transaction of business, come under this general class; which, though on the supposition that they cannot be proved to be in themselves positively wrong or forbidden, have much the “appearance” of evil, and will be so interpreted by others. The safe and proper rule is to lean always to the side of virtue. In these instances it may be certain that there will be no sin committed by abstaining; there may be by indulgence.’

Now, Paul does have some teaching about abstaining from certain things which, though not evil in themselves, might seem to be evil to ‘weaker brethren’, but that it not what he is talking about here.  And, in any case, some of our older brothers and sisters went even further in misapplying this text when they would, for example, allow the viewing of films (movies) at home on the TV, but not in the cinema, because the latter would be apparent to non-Christians, and constitute a ‘bad witness’.