Turn to any page of St. Faustina’s Diary, and you’ll find spiritual gems, like this one:

I became absorbed in prayer and said my penance. Then I suddenly saw the Lord, who said to me, My daughter, know that you give Me greater glory by a single act of obedience than by long prayers and mortifications. Oh, how good it is to live under obedience, to live conscious of the fact that everything I do is pleasing to God! (Diary, 894).