John Thomas (12 April 1805 – 5 March 1871) was an English religious leader, the founder of the Christadelphian movement. He was a Restorationist, with doctrines similar in part to some 16th-century Antitrinitarian Socinians and the 16th-century Swiss-German pacifist Anabaptists. Early life John Thomas was born in Hoxton Square, Hackney, London, on 12 April 1805, was the son of a Dissenting minister, also named John Thomas. His family is reputed to be descended from French Huguenot refugees. His family moved frequently, as his father took up various pastorships including a congregation in London, a brief stay in northern Scotland, back to London, and then to Chorley, Lancashire. At the age of 16, in Chorley, he began studying medicine. His family moved back to London, but John Thomas stayed in Chorley. After two years, he returned to London to continue his studies at the Guy's and St Thomas's hospitals for a further three years. He trained as a surgeon and had an interest in chemistry and biology, publishing several learned medical articles for The Lancet, one of which argued in favour of the importance of the use of corpses for the study of medicine (it was illegal in England to dissect them at this time). Association with Alexander Campbell The Marquis of Wellesley docked in New York and Thomas travelled on to Cincinnati, Ohio where he became convinced by the Restoration Movement of the need for baptism and joined them in October 1832. He soon came to know a prominent leader in the movement, Alexander Campbell, who encouraged him to become an evangelist. He spent his time travelling around the eastern States of America preaching, until eventually settling down as a preacher in Philadelphia. It was here on 1 January 1834 that he married Ellen Hunt. Thomas also wrote for and was editor of the Apostolic Advocate which first appeared in May 1834. His studies during this period of his life generated the foundation for many of the beliefs he came to espouse as a Christadelphian and he began to believe that the basis of knowledge before baptism was greater than the Restoration Movement believed and also that widely held orthodox Christian beliefs were wrong. Whilst his freedom to believe his unique beliefs was accepted, many objected to the preaching of these beliefs as necessary for salvation. This difference led to a series of debates particularly between Thomas and Alexander Campbell.