ISTM that Paul is saying to avoid any type of [actual] evil. I say this because in the context he urges the Thessalonians to examine everything first. In other words, prior to examination one doesn't know if something is actually evil because it could be:
1) something that appears good and is actually good. <-- hold fast
2) something that appears good but is actually evil. <-- shun
3) something that appears evil and is actually evil. <-- shun
4) something that appears evil but is actually good. <-- hold fast
AFTER having examined everything and determined which things are which Paul wants them to shun those things that fit in #2 or #3 which will include some things that had the appearance of good and to embrace #1 and #4 things even though they had the appearance of evil.
The appearance of evil is not what Paul is concerned with, only that which after examination, regardless of appearance (including apparent goodness) is actually a form of evil.
The context of his admonition is the problem of prophecies. He warns not to toss out the "good prophecy baby" with the "evil prophecy bathwater" as is often practice within denominations/sects). They completely suppress speech that does not come top down from "headquarters". Paul wants them to highly value prophecy (which was what Paul wanted most from everyone):
1Co 14:1 Keep on pursuing love, and keep on desiring spiritual gifts,
especially the ability to prophesy. 1Co 14:2 For the person who
speaks in another language is not actually speaking to people but to
God. Indeed, no one understands him, because he is talking about
secrets by the Spirit. 1Co 14:3 But the person who prophesies speaks
to people for their upbuilding, encouragement, and comfort. 1Co 14:4
The person who speaks in another language builds himself up, but the
person who prophesies builds up the church. 1Co 14:5 Now I wish that
all of you could speak in other languages, but especially that you
could prophesy. The person who prophesies is more important than the
person who speaks in another language, unless he interprets it so that
the church may be built up.
This is the "breath fire" that he does not want quenched. But conversely he does not want them to accept every message uncritically. His "better approach" is to allow each to prophesy while the others must judge and then embrace what is good; the rest can be ignored/"abstained from":
1Co 14:26 What, then, does this mean ["better approach"], brothers?
When you gather, everyone has a psalm, teaching, revelation, other
language, or interpretation. Everything must be done for upbuilding.
1Co 14:27 If anyone speaks in another language, only two or three at
the most should do so, one at a time, and somebody must interpret.
1Co 14:28 If an interpreter is not present, the speaker should remain
silent in the church and speak to himself and God. 1Co 14:29 Two
or three prophets should speak, and others should weigh carefully what
is said. 1Co 14:30 If a revelation is made to another person who
is seated, the first person should be silent. 1Co 14:31 For
everyone can prophesy in turn, so that everyone can be instructed and
everyone can be encouraged. 1Co 14:32 The spirits of prophets are
subject to the prophets, 1Co 14:33 for God is not a God of
disorder but of peace. As in all the churches of the saints,
While not a Pauline parable, this parable of Jesus has a lot of overlap with this "better approach":
Mat 13:24 He presented another parable to them, saying, "The kingdom
from heaven may be compared to a man who sowed good seed in his field.
Mat 13:25 While people were sleeping, his enemy came and sowed weeds
among the wheat and went away. Mat 13:26 When the crop came up and
bore grain, the weeds appeared, too. Mat 13:27 The owner's servants
came and asked him, 'Master, you sowed good seed in your field, didn't
you? Then where did these weeds come from?' Mat 13:28 He told them,
'An enemy did this!' The servants asked him, 'Then do you want us to
go and pull them out?' Mat 13:29 He said, 'No! If you pull out the
weeds, you might pull out the wheat with them. Mat 13:30 Let both
grow together until the harvest, and at harvest time I will tell the
reapers, "Gather the weeds first and tie them in bundles for burning,
but bring the wheat into my barn."'"
Paul's prescriptions for the assemblies is almost universally ignored in favor of control mechanisms such as "denominational headquarters", "ordination", "dogmas", "creeds", "councils", etc., none of which Paul had any stomach for. We are told that Paul's ideas are from a simpler time.