His grandmother employed a maid, Sarah White, who invited nine-year-old Reynolds to attend an LDS Church meeting with her.

[3]: 7  In 1863, Reynolds was reassigned as a missionary to the Liverpool area to work as a clerk for church apostle and mission president George Q. Cannon.

As mission clerk, Reynolds organized and coordinated efforts to assist European church members in emigrating to Utah Territory.

[2]: 208 In May 1871, Young asked Reynolds to assist apostle Albert Carrington in publishing the Millennial Star, a church newspaper for British Latter-day Saints.

In September of 1871 Carrington was required to return to the United States, leaving Reynolds as the de facto president of the church's European Mission.

[4] At this time, Young continued to employ Reynolds as the secretary to the First Presidency and also appointed him to be the manager of the Salt Lake Theatre.

[1] In 1874, strong efforts were being made to prosecute Latter-day Saints who practiced polygamy in violation an 1862 Morrill Anti-Bigamy Act.

[5] Confident that the law would be declared to be an unconstitutional violation of the Free Exercise Clause of the First Amendment to the United States Constitution, the leaders of the church agreed to furnish a defendant for a test case.

On appeal, the indictment was overturned by Utah Territory's Supreme Court because the grand jury had not been empaneled in compliance with the Poland Act.

[7][4] On October 30, 1875, Reynolds was indicted a second time; he was found guilty of bigamy by a jury on December 9 and sentenced to two years imprisonment of hard labor and a fine of five hundred dollars.

The court rejected his argument that the Latter-day Saint practice of plural marriage was protected by the Free Exercise Clause of the First Amendment to the Constitution.

After his failed appeal to the Supreme Court, Reynolds was transferred from a jail in Utah to the Nebraska State Penitentiary in Lincoln, where he became U.S. Prisoner Number 14 and was appointed to be the knitting department bookkeeper.

[9] Upon his release from prison, Reynolds resumed his position as secretary to the First Presidency; he also became an active organizer within the Deseret Sunday School Union (DSSU), acting as the editor of and writing many articles for its publication, the Juvenile Instructor.