Why do we see religious extremism on such a rise? What factors are at play in triggering people to use religious sentiments for committing such violent acts?
Intolerance to others religion rituals, ignorance and propaganda triggers religious extremism. People tend to fear what they don't understand.
But the main reason is bunch of evil and corrupted people. They can do anything for their interests. For them it's all about power.
This article might help you:
https://www.frontiersin.org/articles/10.3389/fpsyg.2019.02560/full