I refer to the letter No turning back in Islam in which the author makes some factual errors leading to some seriously wrong conclusions.
The writer claims to know the meaning of being a Muslim as follows: 'A Muslim is a person who is a follower of Prophet Muhammad (peace be upon him) i.e. someone who professes Islam as his/her religion.'
If we read our Quran, we learn that even Ibrahim (peace be upon him) was Muslim. He certainly was not a follower of Prophet Muhammad (peace be upon him).
Yet no one (I hope), would label Ibrahim as an apostate. In addition, we must note that a Muslim is not 'one who professes' Islam but one who 'embraces' it.
It is certainly a failure in the sight of Allah for a Muslim to turn away from the straight path, but current Syariah laws are largely based on texts and human decisions other than the Quran.