Mark 9:38-42:“Teacher,” said John, “we saw someone driving out demons in your name and we told him to stop, because he was not one of us.” 39 “Do not stop him,” Jesus said. “For no one who does a miracle in my name can in the next moment say anything bad about me, 40 for whoever is not against us is for us. 41 Truly I tell you, anyone who gives you a cup of water in my name because you belong to the Messiah will certainly not lose their reward."
That's the bottom line.
the testimony of Jesus is the spirit of prophecy. Rev. 19:10