No other man has stirred more religious controversy — or fervor — than Joseph Smith. Over a 24-year period of time, from 1820 to 1844, he received scores of published revelations, plus power from Jesus, to restore His Authority, Priesthood and original New Testament Church, complete with twelve living and divinely chosen Apostles to serve upon this earth. Due to wickedness and persecution, Christ’s N.T. Church no longer existed within about 150 years after Christ’s resurrection.
Point being, if Joseph Smith truly was God’s prophet, then every other church on this entire planet is false. God does not spread confusion, only Satan does that.
In 1844, Joseph and his brother, Hyrum, were shot and killed by an armed mob of 500 men, at Carthage, Illinois, but Christ’s Church continued under the Apostles.
Why is a true church necessary? In the Bible, there are three degrees of glory, after final judgment. See: I Corinthians, Chap. 15, verses 40–41.
More is clarified in Section 76 of the Doctrine and Covenants, which is a revelation from Jesus Christ, to inform the world what Heaven is all about. The obedient obtain a higher glory than the disobedient, and it takes a church that is connected to Jesus Christ, to both inform the truth and to administer the covenants of exaltation.
For example, the first covenant for exaltation is baptism, by immersion, for the remission of sin. This baptism must be performed by one who has Christ’s true Priesthood to perform this divine covenant and ordinance with Christ. If there is no authority by means of an unbroken line to Christ, then no sin is removed.
No such line existed on earth, so on May 15, 1829, Jesus sent the resurrected John the Baptist to Joseph Smith and Oliver Cowdery to restore Christ’s lost authority to perform a valid baptism. This restoration distinguishes Christ’s Church from all other denominations. The result is that now all who desire, and have faith, may be made clean and gain the highest realm, as stated in I Corinthians, Chapter 15, verse 40.
This book details the reality of this restoration, which the Holy Ghost will so testify.