Killing in the name of religion makes it a cult
A true religion, to me, doesn’t justify killing in its name, as in for its cause. Anybody who uses religion to justify killing has warped it enough that it is no longer true to that religion. In that case, it’s some other thing they are worshiping. In English, we have a word for that, and it’s cult.
The word doesn’t actually carry any of the negative connotations people associate with the word, but that’s how it’s perceived, and that’s how I mean it in this quote. With every negative connotation you want to put to it.