1 Samuel 21:15

Have I need of madmen that ye have brought this fellow to play the madman in my presence? The king evidently feared personal harm from David, who, as he thought, had gone insane. While David's plan to remain unrecognized among the Philistines did not succeed, the presence of mind which caused him to simulate an attack of insanity undoubtedly saved his life. Thus God is able to protect and to deliver His children in the midst of the enemies. Without His will not one hair of our heads falls to the ground.