In Inception, Cobb (Leonardo DiCaprio’s character) explains the central premise of the film: “What is the most resilient parasite? Bacteria? A virus? An intestinal worm? An idea. Resilient... highly contagious. Once an idea has taken hold of the brain it's almost impossible to eradicate.” Cobb and his colleagues can sneak into the dreams of other people, and their goal is to implant an idea so deeply in the persons mind that it grows and captures the imagination. Therefore, the most cherished desires of the heart matter more than any argument. 

 

It’s an interesting idea, but it is basically an old gospel realization. Christianity has, at least since the time of Augustine, insisted on the biblical notion that we act out of the desires of our heart. Our greatest problem is not our desires, but our lack of deep-seated desire for God. In an early nineteenth-century sermon entitled “The Expulsive Power of a New Affection,” Thomas Chalmers said:

 

You have all heard that nature abhors a vacuum. Such, at least, is the nature of the heart, that thought the room which is in it may change one inmate for another, it can not be left void without pain of most intolerable suffering. It is not enough, then, to argue the folly of an existing affection… It may not even be enough to associate the threats and terrors of some coming vengeance with the indulgence of it. The heart may still resist every application, by obedience to which it would finally be conducted to a state so much at war with all its appetites as that of downright inanition... The best way of casting out an impure affection is to admit a pure one; and by the love of what is good to expel the love of what is evil. Thus it is, that the freer gospel, the more sanctifying is the gospel; and the more it is received as a doctrine of grace, the more will it be felt as a doctrine according to godliness. This is one of the secrets of the Christian life, that the more a man holds of God as a pensioner, the greater is the payment of service that He renders back again.

 

Similarly, about a century later, C. S. Lewis, in “The Weight of Glory,” puts it this way:

 

The New Testament has lots to say about self-denial, but not about self-denial as an end in itself. We are told to deny ourselves and to take up our crosses in order that we may follow Christ; and nearly every description of what we shall ultimately find if we do so contains an appeal to desire. If there lurks in most modern minds the notion that to desire our own good and earnestly to hope for the enjoyment of it is a bad thing, I submit that this notion has crept in from Kant and the Stoics and is no part of the Christian faith. Indeed, if we consider the unblushing promises of reward and the staggering nature of the rewards promised in the Gospels, it would seem that Our Lord finds our desires, not too strong, but too weak. We are half-hearted creatures, fooling about with drink and sex and ambition when infinite joy is offered us, like an ignorant child who wants to go on making mud pies in a slum because he cannot imagine what is meant by the offer of a holiday at the sea. We are far too easily pleased.