Printed from http://tektonics.org/foror.php
Matt. 12:30 He that is not with me is against me; and he that gathereth not with me scattereth abroad.
Mk. 9:40 For he that is not against us is on our part.
Lk. 9:50 And Jesus said unto him, Forbid him not: for he that is not against us is for us.
Skeptics see a difference in the "default" position: for or against? But simply put, there is no default.
Where is the middle ground with Jesus? The New Testament, including the Gospels, present Jesus as the focal point of life; the Gospels have Jesus offering himself as the OT figure of Wisdom (Prov. 8), commended to all men.
Is there a middle ground for ultimate wisdom and truth? No, there isn't. Indeed, as Pilch and Malina note in Handbook of Biblical Social Values, in the ancient world all things were viewed in dualistic terms and there was no possible middle ground.
The sayings differ in form and verbiage, but not in essence -- the message is the same, and the differences are attributable to natural variations in oral tradition (as indeed Mark and Luke, though they agree in "default", vary in verbiage).
That said: All of the passages have a context involving the casting out of demons. In Matthew, we find Jesus admonishing the Pharisees after they have claimed that Jesus casts out demons by Beelzebub. In the latter two, we find Jesus teaching the disciples after they complain that a man is casting out demons in Jesus' name. In neither case, in terms of context, is Jesus dealing with a default position.