As well as studying matters of the heart which have little importance attached to them.
Denying divine Decree
Sheikh Abu Hassan Al-Shadhali (may his secret be sanctified) said, “One attribute nullifies actions and most of the people are unaware of it: the anger of the servant about the decree of Allah (the Exalted). The Exalted has said, ‘That is because they disliked what Allah descended so their actions were nullified.’” (Quran: Muhammad 9 and Hikam Al-Shadhali 58).
Decree is part of belief and its important to give Allah (the Exalted) the benefit of the doubt. We should know that things always work out for the best. We should not allow ourselves to get to caught up in the moments of emotion, even though its very easy.
Please see previous post on divine decree click here.