Islamist is a fabricated term to seperate the belief – by Muslims – of the divine laws of Allah and the messenger of Allah, from the violence which was ordered to be carried out until the day of judgement.
Islam cannot evolve from the fundamental beliefs which are believed to be the word of the Islamic God and the messenger of that God, Muhammad.
It’s punishable by death to change anything.
Muslims are reminded many times the penalty for anyone who disobeys Allah and his messenger, the punishment verses mentioned in the Qur’an of hellfire for anyone who disobeys are too numerous to mention. And just in case that didn’t drum it in enough, there are the ahadith from the messenger of Allah which go into more more detail.
Muhammad said at the final pilgrimage at Mount Arafat, that Islam was complete and is also in the Quran, 5/3.
Just how many more times does the Qur’an mention that is perfect, divine, absolute?
Any muslim who genuinely disagrees with what I just said is despised by Allah in Islamic belief and their abode will be the fire of hell.