C. S. Lewis (1900-1963) was certainly one of the most important Christian voices of the 20th century. Even in the 21st century, his influence continues to be felt. For years he taught medieval literature at Oxford. He was both an outstanding scholar and writer.
The following are excerpts from his book Mere Christianity. (Perhaps you have heard C. S. Lewis quoted but have never actually read one of his books. Mere Christianity is absolutely one of his finest! You might consider starting with this one.) These excerpts are from a section of that book in which Lewis discusses the question "Is Christianity hard or easy?"
…The Christian way is different: harder, and easier. Christ says "Give me All. I don’t want so much of your time and so much of your money and so much of your work: I want You. I have not come to torment your natural self, but to kill it. No half-measures are any good. I don’t want to cut off a branch here and a branch there, I want to have the whole tree down. I don’t want to drill the tooth, or crown it, or stop it, but to have it out. Hand over the whole natural self, all the desires which you think innocent as well as the ones you think wicked — the whole outfit. I will give you a new self instead. In fact, I will give you Myself: my own will shall become yours."
…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 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 — centered on money or pleasure or ambition — and hoping, in spite of this, to behave honestly and chastely and humbly.
…That is why the real problem of the Christian life comes where people do not usually look for it. It comes the very moment you wake up each morning. All your wishes and hopes for the day rush at you like wild animals. And the first job each morning consists simply in shoving them all back; in listening to that other voice, taking that other point of view, letting that other larger, stronger, quieter life come flowing in. And so on, all day. Standing back from all your natural fussings and frettings; coming in out of the wind.
… We can only do it for moments at first. But from those moments the new sort of life will be spreading through our system: because now we are letting Him work at the right part of us. It is the difference between paint, which is merely laid on the surface, and a dye or stain which soaks right through.
(Cited in Richard Foster’s Devotional Classics, pp. 8-9.)