Mark 9:40 YLT

³⁸  And John did answer him, saying, 'Teacher, we saw a certain one in thy name casting out demons, who doth not follow us, and we forbade him, because he doth not follow us.'

³⁹  And Jesus said, 'Forbid him not, for there is no one who shall do a mighty work in my name, and shall be able readily to speak evil of me:

⁴⁰  for he who is not against us is for us;

⁴¹  for whoever may give you to drink a cup of water in my name, because ye are Christ's, verily I say to you, he may not lose his reward;

⁴²  and whoever may cause to stumble one of the little ones believing in me, better is it for him if a millstone is hanged about his neck, and he hath been cast into the sea.