Mark 9:
38 “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.
vs
Matthew 12:
30 “Whoever is not with me is against me, and whoever does not gather with me scatters. 31 And so I tell you, every kind of sin and slander can be forgiven, but blasphemy against the Spirit will not be forgiven. 32 Anyone who speaks a word against the Son of Man will be forgiven, but anyone who speaks against the Holy Spirit will not be forgiven, either in this age or in the age to come.
These are two completely conflicting fundamental values here. Matthew's account has Jesus sounding like an Al Quaida leader and Mark makes Jesus sound like Buddah. I cannot possibly attribute both statements to the same person... so one has to go. Since Mark was written first, I'll take his account.
-Sab