Bitterness seeps into the basement of our lives like run-off from a broken sewer pipe. Every form of ugliness begins to float to the surface of those murky waters: prejudice and profanity, suspicion and hate, cruelty and cynicism. There is no torment like the inner torment of bitterness, which is the by-product of an unforgiving spirit. It refuses to be soothed, it refuses to be healed, it refuses to forget. There is no prison more damaging than the bars of bitterness that will not let the battle end.
Charles R. Swindoll, Growing Strong in the Seasons of Life (Portland, OR: Multnomah, 1983), p. 248