There is no question that the divine decree extends along with the level of our own efforts and hard work. The verses of the Quran have explicitly mentioned this issue: “and that nothing belongs to man except what he strives for” and “Every soul is hostage to what it has earned”.
Yet if we look past the circle of our own efforts and struggles, the divine decree can be seen operating and whatever God decides based on his wisdom can be put in to place. This all relates to what is best for human beings and it is something intertwined with human effort and struggle, as well as the decisions of God, who is better able to see what is best for his creation.
 Surah Najm, verse 39.
 Surah Muddathir, verse 38.
 Taken from the text: Tafsīr Nemūneh, Ayatollah Makarem Shirazi, Dār al-Kutub al-Islāmīyah, 36th Edition, vol. 7, p. 521.