We all want progress, but if you're on the wrong road, progress means doing an about-turn and walking back to the right road; in that case, the man who turns back soonest is the most progressive. C. S. Lewis (British writer and literary scholar)

It may be hard for an egg to turn into a bird: it would be a jolly sight harder for it to learn to fly while remaining an egg. We are like eggs at present. And you cannot go on indefinitely being just an ordinary, decent egg. We must be hatched or go bad. C. S. Lewis (British writer and literary scholar)

Has this world been so kind to you that you should leave with regret? There are better things ahead than any we leave behind. C. S. Lewis (British writer and literary scholar)

If the whole universe has no meaning, we should never have found out that it has no meaning: just as, if there were no light in the universe and therefore no creatures with eyes, we should never know it was dark. Dark would be without meaning. C. S. Lewis (British writer and literary scholar)

A man can no more diminish God's glory by refusing to worship Him than a lunatic can put out the sun by scribbling the word, 'darkness' on the walls of his cell. C. S. Lewis (British writer and literary scholar)

Aim at heaven and you will get earth thrown in. Aim at earth and you get neither. C. S. Lewis (British writer and literary scholar)

There are two kinds of people: those who say to God, 'Thy will be done,' and those to whom God says, 'All right, then, have it your way.' C. S. Lewis (British writer and literary scholar)

If I find in myself a desire which no experience in this world can satisfy, the most probable explanation is that I was made for another world. C. S. Lewis (British writer and literary scholar)

Christianity, if false, is of no importance, and if true, of infinite importance. The only thing it cannot be is moderately important. C. S. Lewis (British writer and literary scholar)

If you look for truth, you may find comfort in the end; if you look for comfort you will not get either comfort or truth only soft soap and wishful thinking to begin, and in the end, despair. C. S. Lewis (British writer and literary scholar)

I believe in Christianity as I believe that the sun has risen: not only because I see it, but because by it I see everything else. C. S. Lewis (British writer and literary scholar)

The safest road to hell is the gradual one - the gentle slope, soft underfoot, without sudden turnings, without milestones, without signposts. C. S. Lewis (British writer and literary scholar)

Miracles are a retelling in small letters of the very same story which is written across the whole world in letters too large for some of us to see. C. S. Lewis (British writer and literary scholar)

Miracles do not, in fact, break the laws of nature. C. S. Lewis (British writer and literary scholar)

I gave in, and admitted that God was God. C. S. Lewis (British writer and literary scholar)

There is no uncreated being except God. God has no opposite. C. S. Lewis (British writer and literary scholar)

Humility is not thinking less of yourself, but thinking of yourself less. C. S. Lewis (British writer and literary scholar)

The idea that once a path is taken, one cannot go back and take the other path is called "counterfactual logic" or logic that is "counter to fact" as in not the path taken in reality.

Humans tend to reason in counterfactual logic as in terms of "what if" questions and thoughts.

Spreadsheets became popular as a tool with which to ask "what if" questions for planning and forecasting. C. S. Lewis (1898-1963) makes this a part of his Narnia series of novels in that once a choice is made, one cannot go back nor see what would have happened.

More: 1 Peter 2: The powerful goodness of virtue

Be careful, lest in casting out your demon, you exorcise the best thing in you Friedrich Nietzsche (German philosopher, culture critic)
This might be contrasted with the C. S. Lewis idea of a grumbler becoming a grumble.

More: Friedrich Nietzsche

J. R. Tolkien was a devout Catholic and a contemporary and friend of C. S. Lewis. Tolkien incorporated many Biblical principles into his works such as "The Hobbit" and "The Lord of the Rings".
In "The Lord of the Rings", The wizard Gandolf does not want the ring, the "Ring to rule them all", as he knows that it's power would tempt and corrupt him. This appears to be motivated by the part of the Lord's prayer that goes "and lead us not into temptation".

More: Absolute power

More: J. R. Tolkien