Back in Ohio in early 1835, Joseph Smith was instructed by revelation to call twelve men as Apostles of Jesus—a traveling high council to act as special witnesses to Christ. All those selected were veterans of the army of Israel, and they received their apostolic charge from Oliver Cowdery who told them: "The adversary has always sought the life of the servants of God; you are therefore to be prepared at all times to make a sacrifice of your lives, should God require them in the advancement and building up of His cause."
The Twelve Apostles were sent on a five-month mission to the East Coast to preach, to regulate and strengthen local Mormon congregations, and to raise funds for the construction of the Kirtland Temple. During their travels through New England, New York, and Canada, God's power was with them, and they healed the sick and cast out devils.
The Twelve Apostles were among among the first to be taught by Smith about Jesus's commandment to practice plural marriage (ie. the marriage of one man to more than one wife). Smith told them that when he had hesitated about obeying this commandment, an angel appeared to him and commanded him to begin marrying other women. Smith seems to have first acted on this by marrying his household maid Fanny Alger in the mid 1830s.
In the summer of 1835, a man named Michael Chandler was touring cities of the US with several mummies and papyrus scrolls that had been discovered in Egypt. Having heard that Joseph Smith could translate ancient records, Chandler visited the prophet at Kirtland. As Smith examined the papyri, he received a revelation from Jesus that these were sacred documents, and so the Church purchased them for $2,400 (about $70,000 in today's currency).
As the prophet worked at translating the writings on these papyri, the Saints were thrilled to find out that they contained the writings of the Old Testament patriarch Abraham, from his time in Egypt around 1800 BC. This material, which includes stories of Abraham learning about Jesus, Satan, Creation, and the premortal existence, formed what became known as the Book of Abraham, later recognized by the Church as holy scripture.
1835 also saw the publication in Kirtland of about a hundred revelations of Jesus Christ to Joseph Smith in a compilation titled Doctrine and Covenants, which was also later recognized as being part of the Church's holy scriptures. The book was introduced at a Church conference in August where the prophet proclaimed that these revelations should be treasured more than the riches of the entire world.
After being chastised by Jesus in 1833 for their lack of progress on building the Kirtland Temple, the Saints devoted themselves more faithfully to the task. For three years, nearly every able-bodied man who was not serving on a mission was working on the temple, whether in the quarry or on site, and Church members were called on to pay the supply costs of the temple as well. Because mobs threatened to destroy the temple, it was continually surrounded by armed guards.
The temple was completed in early 1836, and in the first half of that year there were more divine manifestations than in any other period in the history of the Church. There was much speaking in tongues; angels were seen by Church members on at least ten occasions; and at five Church gatherings, Jesus Christ himself was seen. The prophet received a glorious vision of heaven, and saw that his deceased brother Alvin was there.
One of the most significant occurrences in religious history happened on April 3, when Jesus Christ, Moses, Elias, and Elijah visited the prophet and Oliver Cowdery inside the temple, and restored to earth the priesthood power to seal family bonds eternally. From this point forward, Saints in good standing could bring family members to a temple for a ritual that would ensure that their family bonds would remain intact throughout the eternal afterlife.
To this day, in every Jewish home at Passover, a chair at the table is left empty and the door is opened to permit the long-prophesied return of Elijah the prophet as forerunner of the Messiah. But when Elijah finally did return to earth, it was with Jesus Christ at the Kirtland Temple in Ohio.