My thesis: Mormon Church originated as a SEX cult
(posted on a message board; minor revision for this post for lay readers)
We know Joseph Smith invented Book of Mormon (abbreviated BOM) with the help of conspiring fellows Sidney Rigdon and perhaps Oliver Cowdery to scam the gullible people for money.
Let us consider the possibility that, besides money and control as appealing factors for Joseph Smith's (JS) motive in perpetrating a monstrous fraud, Mormon religion was invented to control female subordinates (as second-class citizens) to exploit for sexual relations.
JS came up with polygamy as a convenient excuse derived from his claim that this practice was God's commandment to "replenish" the Earth...to snag as many girls and women as possible to have sex with. See the web link "The Wives of Joseph Smith" for a list that number 34.
I deduce that not only was JS a malignant narcissist with messiah complex (seeking riches to avoid physical labor [yes, he was lazy, arduous labor to convincingly fabricate BOM notwithstanding] after dissatisfaction with minimal profit as a treasure digger, using his extraordinary intellect and charm as the weapon to fool enough people to believe and follow him) but also a sex addict.
However, JS's true motive why he chose to create the religion remain a mystery because maybe much of the documents -- his own surviving writings in hundreds of letters, before and after the creation of religion, whether he was in fact literate or semi-literate (1st edition BOM was rife with poor grammar and misspellings) -- is lost so there might not be forensic examination to develop a scientifically credible psychological profile whether JS meets the criteria of narcissism, borderline personality disorder, sexual addiction, etc.
IMO, JS was a sex addict who used his charm to get into the "panties" of young women behind his first wife Emma's back, because he created the religion as a cover to exploit women sexually.
The present Mormon religion retains its origin as a sex cult starting with JS's womanizing and followers/successors' practice of pre-manifesto polygamy.
My theory: this is due to the socio-cultural and -psychological pressure to marry at a young age to begin sexual relations "immediately" within the legally recognized (and 'morally sanctioned' in LDS cult leaders' attitude) boundaries of a traditional marriage before childbearing become part of their young married lives (either start bearing "now" or postpone until higher education and/or ascension of socioeconomic status is attained so they can afford bearing children without burden).
An example that clearly demonstrates the Mormon Church's pressure beseeching young married people to forthwith bear children regardless of their accomplishment in education and socioeconomic status can be found in a 1987 sermon "To the Mothers of Zion."
I know some young Mo people want to get married in the temple so they can start having sex without shame and guilt, like my younger sister who got married at 19 to a RM [returned missionary] man whom she met a couple quarters back.
Young men opt to serve on the mission with two primary goals in mind: honorable reputation as "servant for the Lord" and, depending on personality and attitude, exponentially improve the chance of dating and getting married to TBM [True Believing Mormon] women at the temple in the short time possible so they can get laid with the leaders' blessings to reap the benefits of a sociologically indispensable stature in prestige.
For the LDS Cult leaders, two things are prerequisite to complete mind control by obedience.
1) Control the single Mormon faithfuls by psychological pressure that marriage is preferable to solitary or single life, and;
2) Control the married Mormon faithfuls by the burden of "frequent" childbearing that keep them preoccupied for life until at least the middle age. Of course, top that with "culturally mandatory" tithes and unpaid volunteer services (bishopric, etc).
Is it any wonder why the normal society look down on fundamentalist LDS sects as perverted and immoral, because older men control girls and women by power and, most egregiously, medieval sexual improprieties to molest and impregnate the younger victims?
The whole travesty lies with JS who created the religion partially to exploit girls and women under the cover of divine guidance to fuel his desire for the pleasure of sexual indulgence with multiple flavors.
LDS Cult, present and past, is not different from Raelian UFO cult in a particular aspect.
By controlling the victims' sex lives through instilling the fear of spiritual retribution, you control them. This is the strategy of the LDS Cult leaders, notably Apostle Boyd K. Packer who condemns male masturbation as sinful & filthy in the priesthood sermon in 1976 and, most recently, April 2009. Not different from Catholic Church, either.