Can a Muslim write a biography and publish it? I am asking this as the Hadiths is a biography of our beloved prophet(sallallah alaihi wa sallam), and similarly any other Muslim can write his life details? Although there is one issue here, since anything done when you are alone is known only to the Almighty Allah and HE alone can condone or condemn it unless one has also informed others about it. I think such issues need not be included in the biography of a Muslim?
All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His Slave and Messenger.
It is permissible for the Muslim to write the biography of someone and publish it in a book. However, if this person is still alive, he should ask his permission because this matter is related to him and is his own right. Moreover, one should make sure about the information he is going to write. Also, he should avoid writing things which might be disliked by the owner of the biography, since mentioning something which he dislikes is considered backbiting, even if it exists in him, as stated in the Hadeeth of the Prophet .
Moreover, there is no harm if the Muslim writes something about his personal life, for some of the righteous predecessors did so. For instance, Imaam Ash-Shaafi’i talked about his journey, which was later reported by his student Ar-Rabee’ (Ibn Sulayman) . Also, As-Suyooti wrote his autobiography in his book “Al-Muhadharah” and so did some of the contemporary scholars.
However, it is not permissible for the Muslim to mention the sins he committed, since the Muslim is religiously required to cover up his sins. This is an obligation. It was narrated on the authority of Abu Hurayrah that the Prophet said: "All members of my Ummah will be forgiven except those who expose their wrongdoings. An example of this is that of a man who commits a sin at night and Allah Conceals it; however, in the morning, he would say (to people), ‘O so-and-so, I did such-and-such yesterday.' Thus, at night Allah Conceals his sin but in the morning he exposes himself.” [Al-Bukhari and Muslim]
Allah Knows best.