Charity—giving to the poor—is an essential part of Christian morality. . . . I do not believe one can settle how much we ought to give. I am afraid the only safe rule is to give more than is comfortable. In other words, if our expenditures on comforts, luxuries, amusements, etc. is up to the standard common among those with the same income as our own, we are probably giving too little.

– C. S. Lewis –
Mere Christianity