This saying must be understood in the context of the given situation. Christ is not saying that every kind of neutrality or uncertainty is equal to discipleship. Here it is about a man who had already shown by his deeds that he was not acting against Christ, because he was casting out demons in His name. Thus, the person who is not an open enemy and even practically contributes to the struggle against evil should not be rejected without cause. The Lord humbles their sense of exclusivity and teaches them to recognize God’s work also outside of themselves.