those who are for christ

John said to Jesus,"Teacher, we saw someone driving out demons in your name,and we tried to prevent him because he does not follow us."Jesus replied, "Do not prevent him.There is no one who performs a mighty deed in my namewho can at the same time speak ill of me.For whoever is not against us is for us."

This is today's reading. I ask if the converse is true. Whoever is not for us is against us. Does this Gospel describe two categories that are fully univesal as well as exclusive. Can one be not for us yet not against us? If not P then not P? True that is a tautology. Or if not P or not not P then Q? Let Q be beside us. Perhaps the logic of the statement does demand one or the other. Can we escape P? Well logic is a human construct and not of God's realm, so I am using a hammer to listen to a heartbeat.