Mine know full well that it is better to get on the bad side of an entire infinite plane of infinite planes full of demons rather than risk the ire of a Paladin Order .

But really, I've found that providing honest reward for heroic deeds keeps my players good enough. Back when I started and every plot involved tricking and manipulating the players and trying to cheat them as much as possible, my players also reacted by trying to cheat everybody. Probably under the assumption that the world functioned with only predators and prey, I blame myself. Mostly .