Not necessarily. It can be something as simple as "My spiritual beliefs just happen to align with what I want to do already". If you want to eat meat, it's very tempting to find a "spiritual" reason for doing it. Nobody can question you; it's just what you believe!
Except we need to hold even spirituality to some measurable degree of sanity.
What if someone truly believes that they need to kill someone or a group of people because of their beliefs, that’s not permissible. It’s not rational or logical to let religious beliefs be a free card to do whatever shit they want.
There are established criteria of what defines a cult, and any spiritual belief system is not necessarily a cult, unless it meets all of that criteria.