Many years ago, early in my ministry, I wrote an article on the growth of the LDS for a leading theological journal. In the process of researching this article I read many of the documents of the Mormon religion including the "Book of Mormon", "Pearl of Great Price" and "Doctrine and Covenants". Personally I was shocked to see how far they have departed from the orthodox Christian faith. What I found in reading and researching the material and speaking to Mormons is that the Mormon religion appeals to a certain type of person, even the Mormon teaching speaks of this fact.
It appeals to one who is analytical in their approach to beliefs and are suspicious of those things that are discerned by faith. The Mormon doctrines have a detailed explanation for everything that Christians accept on faith, most often departing from the implied message of teaching taking advantage of the mystery accepted by faith to use eisegesis in support of their doctrine or doctrines. Contrasting their approach to the Christian approach, theirs is one of reason and intellectual ascension beyond the humble faith of the Christian who is brought to faith by the Spirit where by their belief, no such intellectual ascension is necessary to support their faith. What is a mystery, the Christian is satisfied and accepting of the sovereignty and intellectual superiority of God the Creator and makes no pretense of knowing or even seeking all knowledge of God in this life. We are satisfied as Christians of better understanding what is revealed in Holy Tradition of God and His will than we are in speculating on those things God chose not to reveal to man. With the Mormons, they form entire doctrines based on a few words within Scripture and call it truth because it satisfies and fills the void which for the Christian is filled with faith.
My conclusion was that the Mormon doctrinal teaching will continue to appeal to those needing assurance of knowledge to support their beliefs rather than surrendering to faith. It is a religion that appeals to the desires of the flesh, specifically pridefulness in their all knowing doctrines. It is a religion that tells their followers that they too can become Gods and that only through their religion can one become perfect in this life and pleasing to God in that perfection. This goes far beyond the perfectionism of John Wesley and is a temptation of the flesh. It is a seductive religion drawing its followers within itself rather than towards God.
There is some good in all religions and that is true in that there are good people that are both faithful to the true faith and those who are deceived into false teaching. I believe that there is goodness in Mormon teaching such as their emphasis on the family and their charity towards each other. All that being good, where is the victory if one is robbed of their eternity and they have participated in others falling away from the true faith? Is this a victory for God or for he who wants to decrease the harvest and deceive mankind? This is the danger of man made churches, that they are so vulnerable to apostasy through the fallen nature of man instead of the nature of God which is true perfectionism through Him. We must allow humble surrender to be the epitome of faithfulness. Jesus taught His disciples when they doubted His teaching that it is not the flesh that reveals the truth but the Spirit. Our flesh has little ability to reason the things of God but the Spirit reveals all:
(Joh 6:63 DRB) (6:64) It is the spirit that quickeneth: the flesh profiteth nothing. The words that I have spoken to you are spirit and life.