Why did Joseph Smith. attempt in June 1828 to join the Methodist Church [probationary class] in Harmony, Pennsylvania? In 1820 Joseph Smith had seen two glorious personages, identified as the Father and the Son, and was informed that the creeds of all the “sects,” or various denominations, “were an abomination” and he was twice forbidden to join any of them. So, why did he attempt to join a denomination that God said was an abomination?
1) I think that you may have your dates a little off,
2) you probably never questioned the source of your information; finding it in print, you accepted it as a confirmed fact
So let’s examine your claim for a moment. I can find only three references to the subject of your question. The first one is from Milton V. Backman, Jr., Joseph Smith’s First Vision: Confirming Evidences and Contemporary Accounts, 2d ed. rev., p.198.
“Members of the Smith family could very likely have been attracted to attend meetings held in that community in order to investigate Methodism, to socialize, and to sell goods which they had produced. One contemporary of Joseph Smith, Orsamus Turner, who resided in Palmyra for several years prior to 1822, wrote that “after catching a spark of Methodism in the camp meeting, away down in the woods, on the Vienna road, he [Joseph Smith] was a very passable exhorter in evening meetings.” Another contemporary who lived in Palmyra in 1820, Pomeroy Tucker, verified the religious excitement that was occurring in that part of America at the time of the First Vision. “Protracted revival meetings,” he wrote, were customary in some of the churches, and Smith frequented those of different denominations, sometimes professing to participate in their devotional exercises…. At one time he joined the probationary class of the Methodist Church in Palmyra…. and he soon withdrew from the class. The final conclusion announced by him, was, that all sectarianism was fallacious.”
This account is by someone who left Palmyra “prior to 1822,” who talked of the Smith family, along with Joseph, investigating Methodism, and at “one time joined the probationary class.”
The second account, reproduced below, mentions no date, but states that after attending the probationary class, Joseph came to the conclusion that “all sectarianism was fallacious.” Thus these experiences could well have been before 1820, and certainly not as late as 1828..
“Protracted revival meetings were customary in some of the churches, and Smith frequented those of different denominations, sometimes professing to participate in their devotional exercises. At one time he joined the probationary class of the Methodist Church in Palmyra, and made some active demonstrations of engagedness, though his assumed convictions were insufficiently grounded or abiding to carry him along to the saving point of conversion, and he soon withdrew from the class. The final conclusion announced by him was, that all sectarianism was fallacious, all the churches on a false foundation, and the Bible a fable” (Circumstantial Confirmation of the First Vision Through Reminiscences by Richard Lloyd Anderson , BYU Studies, vol. 9 (1968-1969), Number 3 – Spring 1969, p.383).
The third account is by Dr. B. H. Roberts, a noted church historian, who reports—
“Tucker claims that at one time Joseph Smith, Jun., joined the “probationary class” of the Methodist church in Palmyra, but that he was not carried to the point of conviction, and soon withdrew from the class. (See Tucker’s Origin, Rise and Progress of Mormonism, p. 18.) I find no other evidence that there was any such step taken by Joseph Smith (B. H. Roberts, A Comprehensive History of The Church of Jesus Christ of Latter-day Saints, 6 vols., 1:, p.58).
So the claim of Tucker that Joseph Smith attended any such “probationary classes” is questioned by an eminent researcher of the subject on the grounds that no other reference to such an occurrence on the part of Joseph Smith exists. And, from the first two references, if it did occur it probably occurred before the experience of the First Vision.
If you read the History of Joseph Smith you will find that the family moved to the Palmyra area in 1815. In that record Joseph records,
Some time in the second year after our removal to Manchester, there was in the place where we lived an unusual excitement on the subject of religion. It commenced with the Methodists, but soon became general among all the sects in that region of country…..I was at this time in my fifteenth year. My father’s family was proselyted to the Presbyterian faith, and four of them joined that church, namely, my mother, Lucy; my brothers Hyrum and Samuel Harrison; and my sister Sophronia. During this time of great excitement my mind was called up to serious reflection and great uneasiness; but though my feelings were deep and often poignant, still I kept myself aloof from all these parties, though I attended their several meetings as often as occasion would permit. In process of time my mind became somewhat partial to the Methodist sect, and I felt some desire to be united with them; but so great were the confusion and strife among the different denominations, that it was impossible for a person young as I was, and so unacquainted with men and things, to come to any certain conclusion who was right and who was wrong. My mind at times was greatly excited, the cry and tumult were so great and incessant. The Presbyterians were most decided against the Baptists and Methodists, and used all the powers of both reason and sophistry to prove their errors, or, at least, to make the people think they were in error. On the other hand, the Baptists and Methodists in their turn were equally zealous in endeavoring to establish their own tenets and disprove all others. (JS-H 1:5-9)
It was as a result of these experiences that Joseph determined to ask of God which of all the churches were true, which prayer resulted in the First Vision. So I think that you can rest assured that the Prophet Joseph did not affiliate himself with any sectarian denomination after the First Vision.