Some writers use the word charity to describe not only Christian love between human beings, but also God’s love for man and man’s love for God. About the second of these two, people are often worried. They are told they ought to love God. They cannot find any such feeling in themselves. What are they to do? The answer is the same as before. Act as if you did. Do not sit trying to manufacture feelings. Ask yourself, ‘If I were sure that I loved God, what would I do?’ When you have found the answer, go and do it.

   On the whole, God’s love for us is a much safer subject to think about than our love for Him. Nobody can always have devout feelings: and even if we could, feelings are not what God principally cares about. Christian Love, either towards God or towards man, is an affair of the will. If we are trying to do His will we are obeying the commandment, “Thou shalt love the Lord thy God.’ He will give us feelings of love if He pleases. We cannot create them for ourselves, and we must not demand them as a right. But the great thing to remember is that, though our feelings come and go, His love for us does not. It is not worried by our sins, and our indifference; and, therefore, it is quite relentless in its determination that we shall be cured of those sins, at whatever cost to us, at whatever cost to Him.

Mere Christianity - C.S. Lewis