David Whitmer was first introduced to the Church by his friend Oliver Cowdery. In 1829, after Cowdery had been acting as a scribe for the translation of the Book of Mormon for a few months, he sent a letter to David Whitmer testifying of the prophet Joseph Smith and the Book of Mormon. He also asked Whitmer if they could come to his home to finish translating, due to increasing mob violence in Pennsylvania. A series of miracles convinced Whitmer that this was the path the Lord wanted him to take and brought both the Prophet and Cowdery back to Fayette.
During their time at the Whitmer home, Oliver Cowdery, David Whitmer, and Martin Harris were shown the plates and recorded their testimonies.
Though David Whitmer would be involved in various Church activities over the next several years, a series of small problems and doubts about Joseph Smith’s credibility as a prophet caused the entire Whitmer family to leave the Church. David Whitmer refused to address any charges brought against him, instead preferring to withdraw from the Church. He was excommunicated in 1838 for apostasy.
He ran a successful livery stable business until his death in 1888, never returning to the Church. During those years, he “reorganized” the Church for a time, later confessing they did so without proper authority. Towards the end of his life, he ordained his nephew to “perpetuate the Church of Christ,” which meant sticking only to the doctrines revealed in the beginning of the Church. However, he never did deny his testimony of the Book of Mormon. Shortly before he died, he made a public statement to the local Richmond Conservator newspaper:
“That I have never at any time denied that testimony or any part thereof, which has so long since been published with that Book, as one of the three witnesses. Those who know me best, well know that I have always adhered to that testimony. And that no man may be misled or doubt my present views in regard to the same, I do again affirm the truth of all my statements, as then made and published.”