Religions can't be studied, they can only be practiced, because they are pathways towards God and there's an essence underneath the surface which can only be grasped once you are threading the path offered by the religion in question. Studying it from a distance is pointless because without personal participation the symbols and beliefs that make up the body of a religious system will remain unintelligible and incomprehensible.
It's a bit like trying to "study" the music of Beethoven by reading it on paper. There's no point to it, you won't get it unless you actually experience it.
Also, stick to traditional religions, and to the traditional authorities within those religions (if you are Muslim, avoid Salafi nonsense, if you are a Catholic, stay away from Vatican II etc).
I would stay away from that stuff. If you really need an explanation for why we have multiple religions and what esoterism actually means, i'd would turn to the Perennialists excusively:
Stay away from those false new religions. Baha'i', spiritism, Freemansory, they are all warped.