Christ was no thief, but He allowed Himself to be crucified with and for thieves. Why did He allow this? Love compelled Him to bear the sins of many.
There are two categories of sin: sins against God and sins against man. By default, every sin is against God. Yet, not all sin is against man.
Most people view sin as a private or earthy matter. Yet, every sin is against the Lord. In truth, men can sin against the Father, the Son, and the Spirit.
People in the world are generally quite self-centered. Even saved people are often lovers of their own selves instead of preferring one another.
