Leviticus 13:34
And on the seventh day the priest shall examine the itch, and if the itch has not spread in the skin and it appears to be no deeper than the skin, then the priest shall pronounce him clean. And he shall wash his clothes and be clean.
1 John 4:1
Beloved, do not believe every spirit, but test the spirits to see whether they are from God, for many false prophets have gone out into the world.
Jude 1:22
And have mercy on those who doubt;
Revelation 2:2
"'I know your works, your toil and your patient endurance, and how you cannot bear with those who are evil, but have tested those who call themselves apostles and are not, and found them to be false.