Beware of false prophets.
“Beware of false prophets, who come to you in sheep’s clothing, but underneath are ravenous wolves. By their fruits you will know them. Do people pick grapes from thornbushes, or figs from thistles? Just so, every good tree bears good fruit, and a rotten tree bears bad fruit. A good tree cannot bear bad fruit, nor can a rotten tree bear good fruit. Every tree that does not bear good fruit will be cut down and thrown into the fire. So by their fruits you will know them. “Not everyone who says to me, ‘Lord, Lord,’ will enter the kingdom of heaven, but only the one who does the will of my Father in heaven. Many will say to me on that day, ‘Lord, Lord, did we not prophesy in your name? Did we not drive out demons in your name? Did we not do mighty deeds in your name?’ Then I will declare to them solemnly, ‘I never knew you. Depart from me, you evildoers.’” Matthew 7:15-23
This is one reason Scripture tells us to examine ourselves to see if we are indeed “in the faith.” Many people, not a few, are deluded in thinking they are members of God’s family. We need to examine ourselves and others with whom we interact, especially those who teach or minister in the church. We must not be deluded or led astray by such people. The evidence will be in their lives (and in our lives). They will be doing God’s will. We are not doing them or ourselves any favors by ignoring the evidence. If people are not in the Kingdom of God, they need to know it.