Mark 9:37-39

37 "Whoever receives one of these little children in My name receives Me; and whoever receives Me, receives not Me but Him who sent Me."

38 Now John answered Him, saying, "Teacher, we saw someone who does not follow us casting out demons in Your name, and we forbade him because he does not follow us."

39 But Jesus said, "Do not forbid him, for no one who works a miracle in My name can soon afterward speak evil of Me.