The existence of Evil?

Prof: "What is Evil?" Student Replied: "sir I will explain Evil but first answer my few questions" Prof: "Go Ahead" Student: "Does Cold exist?" Prof: "Yes" Student:"No. There is nothing like cold exist instead there is complete absence of heat. Ok now my second question Does Darkness exist?" Prof: " Yes" Student: "You are wrong sir there is no darkness but always the absence of light" According to Physics we can study "Light" &"Heat" but not "Cold" or "darkness" similarly sir Evil does not exist BUT there is sure absence of Faith , Love and Believe in God"