The spirit of Christianity proclaims the brotherhood of the race and the meaning of that strong word has not been left to guesswork, but made tremendously definite - the Christian must forgive his brother man all crimes he can imagine and commit, and all insults he can conceive and utter - forgive these injuries how many times? - seventy times seven - another way of saying there shall be no limit to this forgiveness. That is the spirit and the law of Christianity.
Mark Twain (1973). “Mark Twain and the three R's: race, religion, revolution--and related matters”, Bobbs-Merrill Company