Our noble brother, Tahrib al-Dawsiri (may Allāh preserve him) gives a phenomenal lecture titled "Reason for Being Firm Upon the Dīn". Allah has not created anything except for a reason, and with wisdom. Everything that Allāh created has been created for a great purpose. If a person knew the wisdom behind everything single little things created, then he would have been the creator, and we know that that is impossible. It is obligatory that we believe in the perfect wisdom of Allāh. He did not leave us without knowing our purpose. Allāh has been so merciful to us that He explained the purpose of our creation and our ultimate goal.
Tarḥīb al-Dawsirī - troid.org | Islamic Articles and Audio
The Prophet (ṣallallāhu ʿalayhī wa-sallam) said "Whoever says Lā ilāha illa-Allāh, it will be his salvation someday, no matter befalls him before that." (This was reported by Bayḥaqī, declared authentic by al-Albānī in Āḥadīth al-Ṣaḥīhah #1932)