Unfaith turns Christianity into only a philosophy. Of course, Christianity is a philosophy -- though not a rationalistic one because we have not worked it out from ourselves. Rather, God has told us the answers. In this sense it is the true philosophy, for it gives the right answers to man's philosophic and intellectual questions. However, while it is the true philosophy, our Father in heaven did not mean it to be only theorectical or abstract. He meant it to tell us about Himself -- how we can get to heaven, but equally, how we can live right now in the universe as it is with both the seen and the unseen portions standing in equal reality. If Christians just use Christianity as a matter of mental assent between conversion and death, if they only use it to answer intellectual questions, it is like using a silver spoon for a screw driver. I can believe that a silver spoon makes a good screw driver at certain times. But it is made for something else. To take the silver spoon that's meant to feed you, moment by moment, and keep it in your tool box to use only as a screw driver is silly. Death in the City (Downers Grove, InterVarsity Press: 1969) 139-40

It is not our circumstances on the outside which are our real problem. It is the circumstances on the inside of us, the unbelief in our hearts, which is the cause of our problems.

Unbelief is actually perverted faith, for it puts its trust not in the living God but in dying men.

In all unbelief there are these two things; a good opinion of one's self, and a bad opinion of God.

Unbelief is not a misfortune to be pitied; it is a sin to be deplored. Its sinfulness lies in the fact that it contradicts the word of the one true God and thus attributes falsehood to him.

Conversion, then, is repentance (turning from sin and unbelief) and faith (trusting in Christ alone for salvation). They are two sides of the same coin. One side is tails -- turn tail on the fruits of unbelief. The other side is heads -- head straight for Jesus and trust his promises. You can't have the one without the other any more than you can face two ways at once, or serve two masters.

Unbelief, in distinction from disbelief, is a confession of ignorance where honest inquiry might easily find the truth. "Agnostic" is but the Greek for "ignoramus."

Our twentieth century, far from being notable for scientific scepticism, is one of the most credulous eras in all history. It is not that people believe in nothing - which would be bad enough - but that they believe in anything - which is really terrible.