:-D
My guess is that most of them are emotionally convinced, as opposed to being intellectually convinced.
I doubt all that many of them actually study and think through the arguments - instead, they decide what they want first and they look around for arguments that seem to support what they already believe - and that will help them get their own way.
Yep. People from all over the world joined Isis for no other reason than that they could kill with (to them) justification. They didn’t give one fig about Islam. They’d mouth the platitudes and kneel on the rugs but never believed any of it. This is often the reason people join such movements. The same with Antifa. They are recruited from prisons and halfway houses and mental hospitals. Same same the SA in Germany. The ideology is only an excuse to commit acts of evil.