There's is such a difference between knowing something is Hashem's will and between actually doing it (or not doing it). I hate that difference. However, I just read something which has enabled me to accept that horrible split between intellect and action, and to accept it with joy.
Everybody knows about the famous question in the first paragraph in the Shema. V'hayu hadvarim ha'aileh ... Al levavecha; "And these words which I command you this day should be on your heart." On your heart? Why not in your heart? I once heard it said that it's really too much to ask of someone, that when one hears a halacha or a new concept, or a different way of how to be a tzadik, that they will bring it into their hearts, even if they agree with it intellectually. Therefore, we put it on our hearts, and wait till there's a little crack, then the Torahs can come in. Rav Avraham Twerski likens the walls of our holy aortas to those of a dam. The waters of Torah are pushing up against the dam, and even if there is the smallest crack, the tiniest crevice in our resistance to a Torah, all the water will eventually go through. It just takes time.
May we all merit to actualize our potential in this world in the greatest way, slowly but surely, and with simcha.