The problem with this question is that it assumes radical terrorism is a direct result of the Islamic belief. It’s not. Just like the KKK aren’t representative of Christianity, terror groups such as ISIS don’t represent Islam.
Most terrorists use the guise of lesser jihad to justify their actions. This is stupid as lesser jihad is about defending the Muslim community, not ironically destroying their own people like ISIS do.
The very definition of Islam is peace and although their holy book may contain lines which are somewhat questionable ethically, the bible is exactly the same.
Judge the individuals, don’t generalise the group.