If a person truly read and understood the Bible they'd realize that they are being mislead. Unfortunately, most people get their Biblical education from the leadership and are pretty ignorant of the true meaning of the Bible.
A little bit of laziness, a little bit of “it feels right so it must be right.”
And there is always the desire to embellish on the message with man created ritual and mantra which eventually ends with the message being corrupted with a power structure and hierarchy created. And the longer a church exists, the more corrupted the message gets.
None of which has anything to do with being a cult. False teachings (whatever I or tradition disagree with) are not a distinguishing characteristic of a cult.