It's wrong to put our own unispired twist on the scriptures. But, many devout Christians over the centuries have studied the Bible and come to different conclusions on all kinds of important issues such as the Trinity, the relationship between faith and works, the role of the Holy Spirit, the need for baptism, the need for any other sacraments, the role of priesthood, pre-destination, what is heaven, what is hell, what are the coomandments, what does it mean to obey God, what does it mean to be saved, what is required to be saved, can one fall from grace, and on and on. Hence we have lots of denominations.
The Mormon Church certainly has teachings that address this subject, that account for the many denominations and that account for it's own existence. (That could be a very lengthy discussion in many separate threads).