This is a rhetorical question. How could you disbelieve in Allah U?! Think of Allah’s U existence, through His giving you life and putting you to death, for He is the One who created death and life.
Death is mentioned before life because death is the evidence that life existed.
The subject of death is the way to approach atheism, as the claims of atheism cannot be refuted except through knowledge and proofs. Therefore, the subject of death can be used to refute the atheists who say: “The intellect alone suffices in managing our lives” and “Do not talk to us about the unseen.” We refute their allegations by saying: “Verily, the One who is in control of giving life to creation is the very One who controls their death. Allah U has demonstrated to us death in its reality and told us all that we have forgotten about our creation:
﴾مَا أَشْهَدْتُهُمْ خَلْقَ السَّمَوَاتِ وَالأَرْضِ وَلا خَلْقَ أَنفُسِهِمْ﴿
“I did not make them witness to the creation of the heavens and the earth or to the creation of themselves” [Surah Al-Kahf: 51].