We must never forget that we are in constant combat. The lives of those under our care and concern depend upon our success. In warfare, one of the most effective tactics of the enemy is a surprise attack. This tactic is used by Satan in the poisonous darts of reviling. "Yea, mine own familiar friend, in whom I trusted, which did eat of my bread, hath lifted up his heel against me (Psalm 41:9)."