Despair is disapproved of in the Quran because one who despairs shows that he does not trust God. When God has declared that the universe is replete with His mercy, to become dejected would mean to have no hope from God. Moreover, God's mercies are not evident in the manner in which stones and rocks are visible. Often we seek a blessing in the present moment but God has kept it for the future, which leads to despair. We should know that God's blessings and bounties sometimes come to us soon and at other times they come later on. It is also possible that we may not receive a blessing we desire in this world because it is meant to be enjoyed in the Hereafter. One who does not reflect on these issues would fall to despair, showing that he does not have trust in God.