Suppose you want to praise someone. What motivates you to do so? (1) To make him or her like you, so you can feel good? (2) To make that person feel good? (3) To please God? The first motivation is definitely impure, for it involves egos. We can be sure that the last motivation is pure. It's not always easy to discern our motivation quickly or in advance if we are not in close union with God. But to be holy, we must aim at keeping our motivation pure.