Jesus already covered all this.
True and False Prophets
15“Watch out for false prophets. They come to you in sheep’s clothing, but inwardly they are ferocious wolves.
16By their fruit you will recognize them. Do people pick grapes from thornbushes, or figs from thistles?
17Likewise, every good tree bears good fruit, but a bad tree bears bad fruit.
18A good tree cannot bear bad fruit, and a bad tree cannot bear good fruit.
19Every tree that does not bear good fruit is cut down and thrown into the fire.
20Thus, by their fruit you will recognize them.
True and False Disciples
21“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 who is in heaven.
22Many will say to me on that day, ‘Lord, Lord, did we not prophesy in your name and in your name drive out demons and in your name perform many miracles?’
23Then I will tell them plainly, ‘I never knew you. Away from me, you evildoers!’