not a belief system for example Zoroastrianism is not a cult they certainly have a different god but the fire worshippers do not claim to be part of Christianity
They are certainly another religion and belief system but would not qualify as a cult.
although you are trying to box it into a hypersyncreatic house which act as a safe space for many that will mean that this house has no foundation of absolute truth.
Jesus was a carpenter reading the Bible I don’t think he got the fix and lock up job on that house
