Islamically, the accountable person (mukallaf) is the one who is pubescent, sane, and has received the message of Islam. Pubescence happens when one reaches the age of fifteen (15) lunar years, or otherwise. The sane person is the one who has not lost one’s mind.
For one to be accountable (mukallaf), it is a condition that one receives the call of Islam. This means that if the person is pubescent and sane, he becomes mukallaf simply by receiving the message of Islam, which is: “No one is God except Allah, and Muhammad is the Messenger of Allah.” The non-believer mukallaf is required to embrace Islam and follow its teachings. He must also perform all the obligations and avoid all the sins.
From this, it is understood that the young child is not accountable until he reaches pubescence. Likewise, the insane person is not accountable. The pubescent one who did not receive the message of Islam is also not accountable.
Allah, ta^ala, said in the Qur’an:
[Wa ma kunna mu^adhdhibina hatta nab^atha rasula.]
Ayah 15 of Suratul-Isra’ means: {Allah does not torture those who do not receive the basic message of Islam.}
The Messenger of Allah, sallallahu ^alayhi wa sallam, said:
Rufi^al qalamu ^an thalathah: ^anin-na’imi hatta yastayqidh, wa ^anis-sabiyyi hatta yahtalim, wa ^anil-majnuni hatta ya^qil.]
Which means: “The pen has been lifted from [writing the deeds of] three: the one who is asleep until awakening, the young child until becoming pubescent, and the crazy person until becoming sane.” (Related by Abu Dawud)
Note:
During the season of Hajj when many of the Arab non-believers used to assemble from different places in Makkah, the Prophet called them to Islam. They would hear from the Prophet the Two Testifications: “I bear witness that no one is God except Allah and that Muhammad is the Messenger of Allah.” The non-believers came to the Ka^bah in keeping with the traditions of their Muslim ancestors.