Mark 9:33-39

³³Then He came to Capernaum; and once in the house He asked them, “What were you debating among yourselves on the road?”

³⁴But they kept silent, because on the road they had debated among themselves who was greater.

³⁵So He sat down, called the twelve and said to them, “If anyone desires to be first, he must be last of all and servant of all.”

³⁶Then He took a child and stood him in their midst, and embracing him said to them,

³⁷“Whoever receives one such child in my name receives me, and whoever receives me receives not only me, but the One who sent me.”

³⁸So John answered Him saying, “Teacher, we saw someone casting out demons in your name, one who doesn't follow us; and we forbade him, because he doesn't follow us.”

³⁹But Jesus said: “Do not forbid him, because no one who works a miracle in my name can soon afterward speak evil of me.