His family on both sides were loyalists who settled in Matilda Township in 1784 on crown land grants after the American Revolutionary War.

[1][3] Carman was converted in the winter of 1854, and was encouraged by his father to join the Methodist Episcopal Church in Canada.

It gave a three-year course in classics, philosophy, mathematics and science to young Methodist Episcopals, both men and women.

[5] Carman made the Belleville Seminary succeed through advocacy within the church and through his ability as a teacher and administrator.

[3] Towards the end of his tenure at Albert College, in 1874 Carman was elected to the Council of Public Instruction.

Other members included Samuel Sobieski Nelles, Egerton Ryerson and the Roman Catholic Bishop Joseph Lynch.

[8] After Richardson died in March 1875 Carman was sole head of the Methodist Episcopal Church.

Carman tried to improve church organization and expand into urban areas and the prairies, but was not successful.

[1] The Methodist General Conference of 1890 proposed to hold ongoing informal discussions about union with Congregationalists and Presbyterians, and if possible with Anglicans and Baptists.

Carman spoke at the 1902 General Conference in favor of serious consideration of union of the Protestant churches.

[12] At the 1911 Ecumenical Methodist Conference in Toronto Carman intervened in a debate on "The Permanent Results of Biblical Criticism".

The British Methodist Recorder said, "Very pathetic it was to see this veteran stand up to plead against conclusions which he deemed harmful, in the presence of an assembly which in the main accepted them."

[15] He was in favor of social reform to make Canada a truly Christian country, but was opposed to radicals who wanted to overthrow the established order.

He distrusted the wealthy laity and looked to the middle classes to take the lead in creating a more "brotherly" society.

[12] During his tenure Carman improved the administration of the Methodist Church, promoted Sabbath observance and fought evils such as dancing, gambling and alcohol.

However he did not prevent, and perhaps enabled, innovation in the church's theology and evangelical tradition to meet modern requirements.