Humanists reject the traditional dualism of mind and body - to them, everything is one.
They believe that there's no difference between and idea and an individual.
God loves all people, but He doesn't love all ideas.
Jesus supports this when He appears to call Peter satan.
A humanist would say that Jesus believed Peter was actually satan, but in reality Jesus was addressing satan himself who was putting bad ideas in Peter's mind.
Jesus spoke to the spirit behind the idea.
Ahithophel believed the humanist way, so when Absalom rejected his idea he took it as a rejection of himself.
His pride led him into this kind of thinking.
Pride is the glue that sticks the idea and individual together so there is no distinction, and we all think like this at times - we have to fight against it.
We tend to believe that we must respect all people and all their ideas, but the teaching of Jesus is the opposite.
When we separate the two we can sharply disagree over a nice steak dinner.