According to Islam, the soul enters the womb of its mother 120 days after conception, which is when the individuation of a soul takes place.
According to Islamic traditions, our souls go through several stages before finally meeting God. The first realm of life is in alam-e-arwah (world of souls), as they existed on the day of Misaq, the primordial covenant. There was a time when all the souls from Adam’s progeny yet to be born were bought forth, “When thy Lord drew forth from the children of Adam — from their loins — their descendants, and made them testify concerning themselves, (saying): ‘Am I not your Lord (who cherishes and sustains you)?’ — they said: ‘Yes! We do testify!’ This, lest ye should say on the Day of Judgment: ‘Of this we were never mindful.’” This verse is the most distinctive theme in the Quran that helps understand that man’s primary duty on earth is to fulfil this covenant with God.
In the second stage, the soul descends from divine presence into duniya, the lowest world in the hierarchy of the universe. According to Islam, the soul enters the womb of its mother 120 days after conception, which is when the individuation of a soul takes place.
The third realm of existence is in the barzakh, an inter space between this world and the next, where people lie in their graves. The fourth is the place of gathering on the Day of Judgment and fifth, the final abode, which is either closeness or alienation from God.
Consistent to some Western theories, the Islamic perspective divides life in this world into seven stages, beginning with infancy. When a child is born to Muslim parents, the azaan (call to prayer) is whispered in the right ear and the takbeer (call to rise) for prayer recited in the left ear. The words are meant to remind the soul of its pre-worldly contract with Allah. The infant is still in a state of unity with God but moving towards separation. The child is in the state of waad (divine promise), which is that all of humanity will return to God. The child remains in this realm of promise till s/he reaches puberty.
Dominant Muslim opinion believes that if someone dies before puberty, s/he shall surely enter paradise; for death arrived before the age of accountability to God.
With puberty begins the second stage of waid (warning), which means that if one does not fulfil obligations to God, there is punishment. However, Allah says, “My mercy precedes my wrath.” Scriptures tell us that Allah has reserved 99 parts of his mercy for the Judgment Day.
The fourth stage arrives at the age of 40, when one reaches the age of maturity. Life after 40 is the age for reflection and perceived as a bounty from God. At the fifth stage of 50 years, men and women are required to compassionate, help and guide young people. At the sixth stage of 70 and beyond, it is time to move inwards into deep meditative states. Death is the final stage, after which each soul will answer for itself.