“We must be ready to allow ourselves to be interrupted by God.” — Dietrich Bonhoeffer

You may remember I said that the first step towards humility was to realise that one is proud. I want to add now that the next step is to make some serious attempt to practise the Christian virtues. A week is not enough. Things often go swimmingly for the first week. Try six weeks. By that time, having, as far as one can see, fallen back completely or even fallen lower than the point one began from, one will have discovered some truths about oneself. No man knows how bad he is till he has tried very hard to be good. A silly idea is current that good people do not know what temptation means. This is an obvious lie. Only those who try to resist temptation know how strong it is. After all, you find out the strength of the German army by fighting against it, not by giving in. You find out the strength of a wind by trying to walk against it, not by lying down. A man who gives in to temptation after five minutes simply does not know what it would have been like an hour later. That is why bad people, in one sense, know very little about badness. They have lived a sheltered life by always giving in. We never find out the strength of the evil impulse inside us until we try to fight it: and Christ, because He was the only man who never yielded to temptation, is also the only man who knows to the full what temptation means—the only complete realist.  

From Mere Christianity Compiled in A Year with C.S. Lewis