I only cheat if it's absolutely necessary. For example, I was playing Half-Life: Episode 1. Somehow, I was left with only one HP, at a portion of the game where you only have the super gravity gun and Alyx's AMAZING A.I. to help you, right in the middle of a big ambush. Needless to say, I got grazed by a single bullet and died every time I tried. So I turned on god mode and promptly turned it off when I got a usable amount of health.