"I do not believe one can settle on how much we ought to give. I am afraid the only safe rule is to give more than we can spare. In other words, if our expenditure on comforts, luxuries, amusements, etc., is up to the standard common among those with the same income as our own, we are probably giving away too little. If our charities do not at all pinch or hamper us, I should say they are too small. There ought to be things we should like to do and cannot do because our charitable expenditure excludes them."
(C. S Lewis in Mere Christianity)
(HT: Vit Z)
Possibly related posts from the past:
1. Tithing and Giving
2. Giving with a Difference