Luke 9:46-50

Then there arose a reasoning among them, which of them should be greatest. And Jesus, perceiving the thought of their heart, took a child, and set him by him, and said unto them, Whosoever shall receive this child in my name receiveth me: and whosoever shall receive me receiveth him that sent me: for he that is least among you all, the same shall be great. And John answered and said, Master, we saw one casting out devils in thy name; and we forbad him, because he followeth not with us. And Jesus said unto him, Forbid him not: for he that is not against us is for us.