I am the Way, the Truth, and the Life. No man comes to the Father except by me. ~ Jesus
The pharisees challenged Jesus, without knowing him. They did not know who he was, just as many don't know who he is now.
The real problem was not one of intellect. It was (and is) a problem of the will. The pharisees spent all their energy trying to devise a way to kill Jesus, and did not care to listen to what he had to say. Many people today are the same way. They claim to have intellectual reservations, but do not bother to research the historical accuracy of the accounts.
The idea of a real God who is intimately involved in our lives, can be somewhat disconcerting.
That is, before you know him. I'm sorry to say that many Christians don't spend enough time KNOWING Him, myself included. We forget that it is about a relationship with our Savior.
That we may know Him.