John 7:24 Do not judge according to appearance, but judge the righteous judgment.

1 John 4:1

Beloved, do not believe every spirit, but test the spirits, whether they are of God; because many false prophets have gone out into the world.

Matthew 7:15-20 You Will Know Them by Their Fruits

“Beware of false prophets, who come to you in sheep’s clothing, but inwardly they are ravenous wolves. You will know them by their fruits. Do men gather grapes from thornbushes or figs from thistles? Even so, every good tree bears good fruit, but a bad tree bears bad fruit. A good tree cannot bear bad fruit, nor can a bad tree bear good fruit. Every tree that does not bear good fruit is cut down and thrown into the fire. Therefore by their fruits you will know them.

1 Corinthians 5:9-13 I wrote to you in my letter not to associate with sexually immoral people— not at all meaning the people of this world who are immoral, or the greedy and swindlers, or idolaters. In that case you would have to leave this world. But now I am writing to you that you must not associate with anyone who claims to be a brother or sister but is sexually immoral or greedy, an idolater or slanderer, a drunkard or swindler. Do not even eat with such people.

What business is it of mine to judge those outside the church? Are you not to judge those inside? God will judge those outside. “Expel the wicked person from among you.”