This is an interesting concept. God is too big to fit into one religion. If this were true, it’d means that every religion is wrong about their view, or lack of a view, of the divine (God).
This is ultimately saying that God is unknowable from one religion alone, and since the teachings of the various religions contradict each other, combing them all into one God-smoothie doesn’t help matters.
Wrong #1 – Christianity, as well as some other religions, claim that God is omnipotent, omnipresent, omniscient, and omnibenevolent. How can God be bigger than that? Is it even possible for a God to exist bigger than a God that is not restricted by time, space, or matter, who is not limited in any ability to do as he wills, he has complete and perfect knowledge of everything, and always acts in ways that are wholly good? I don’t think so. Therefore, it’s completely possible that God can fit into one religion.
Wrong #2 – Religions aren’t containers. They don’t contain God. They’re not boxes that somehow, God conveniently fits into, although some religious adherents treat their religions as such. Religions offer revelations and explanations to who God is. It’s committing a category error to say that “God is too big to fit into one religion.”