Evil is not obvious at first. Evil people do not show their worst face. Their fruit appears only after the flower is gone.
The sins of some people are obvious, going before them into judgment, but for others, they show up later.
1 Timothy 5.24 NET
As Jesus said, by their fruits you shall know them. The wolf in sheep’s clothing looks exactly like a sheep, until at some point he shows his fangs. Erich Fromm wrote on what he called malignant narcissism.
The naïve assumption that an evil man is easily recognizable results in a great danger: one fails to recognize evil men before they have begun their work of destruction… there are enough of them to be very dangerous if they attain influence and power.
This truth should not cause us to suspect everyone or make groundless accusations; it should keep us from laying hands hastily on people we don’t know well (1 Timothy 5.22). It should keep us from tapping new converts for the eldership (1 Timothy 3:6). It should cause us to let candidates to servanthood first be proven (1 Timothy 3:10). Christians must put everything to the test (1 Thessalonians 5.21).
The modern skepticism about the spoken word serves a caution to see if words and works form a person with integrity. It also reminds us that evil, when it is identified sooner or later, must be removed. The earlier the better, for the longer it remains the more opportunity we give it to do its “work of destruction.”
Lord of purity and holiness, purify me so that I may see the presence and effect of evil, to purge it from my heart and from the midst of your people.
Hold this thought: A shrewd person sees danger and hides himself, but the naive keep right on going and suffer for it (Proverbs 22.3; 27.12).