Praise be to Allah.
Both the sperm and the ovum are alive in a sense which, if they are free from defects, prepares each of them to join with the other, if Allaah wills and decrees it to happen. When that happens, if Allaah wills it, the embryo is formed and is also alive in a manner that suits it and prepares it to grow and develop, moving through the known stages. When the soul is breathed into it, it becomes alive in another sense, by the permission of Allaah, the Subtle One, the Aware. No matter how a man tries, even if he is a highly-skilled doctor, he can never comprehend all the secrets and stages of development of pregnancy. Allaah says (interpretation of the meanings):
“Allaah knows what every female bears, and by how much the wombs fall short (of their time or number) or exceed. Everything with Him is in (due) proportion. All-Knower of the unseen and the seen, the Most Great, the Most High.” [al-Ra’d 13:8-9]
“Verily, Allaah! With Him (Alone) is the knowledge of the Hour, He sends down the rain, and knows that which is in the wombs…” [Luqmaan 31:34]
(Fataawa Islamiyyah li’l-Lajnah al-Daa’imah, 488).
Life is of varying kinds, and each being is alive in a manner that suits it by the power of Allaah. So plants are alive in a manner that suits them, sperm is alive in a manner that suits it, and man is alive in a manner that suits him, and so on. Allaah is the Creator of all this, and He has made water the basis of every living thing, as He says in the Qur’aan (interpretation of the meaning):
“Have not those who disbelieve known that the heavens and the earth were joined together as one united piece, then We parted them? And We have made from water every living thing. Will they not then believe?” [al-Anbiya’ 21:30]
And Allaah knows best.