Lewis on the Lazy

Teachers will tell you that the laziest boy in the class is the one who works hardest in the end. They mean this. If you give two boys, say, a proposition in geometry to do, the one who is prepared to take trouble will try to understand it. The lazy boy will try to learn it by heart because, for the moment, that needs less effort. But six months later, when they are preparing for an exam, that lazy boy is doing hours and hours of miserable drudgery over things the other boy understands, and positively enjoys, in a few minutes. Laziness means more work in the long run. Or look at it this way. In a battle, or in mountain climbing, there is often one thing which it takes a lot of pluck to do; but it is also, in the long run, the safest thing to do. If you funk it, you will find yourself, hours later, in far worse danger. The cowardly thing is also the most dangerous thing.
It is like that here. The terrible thing, the almost impossible thing, is to hand over your whole self - all your wishes and precautions - to Christ. But it is far easier than what we are all trying to do instead. For what we are trying to do is to remain what we call 'ourselves', to keep personal happiness as our great aim in life, and yet at the same time be 'good'. We are all trying to let our mind and heart go their own way - centred on money ore pleasure or ambition - and hoping, in spite of this, to behave honestly and chastely and humbly. And that is exactly what Christ warned us you could not do. As He said, a thistle cannot produce figs. If I am a field that contains nothing by grass-seed, I cannot produce wheat. Cutting the grass may keep it short: but I shall still produce grass and no wheat. If I want to produce wheat, the change must go deeper than the surface. I must be ploughed up and re-sown

From Mere Christianity