He was the great-great-great-grandson of George Soule, who in 1620 arrived at Plymouth, Massachusetts as a Mayflower Pilgrim, eventually becoming a prominent Duxbury landowner.

Although his parents were strict Presbyterians, the adolescent Joshua Soule converted to the Methodist Episcopal faith in 1797, joining the New England Annual Conference in 1799.

Tall, dignified and able, Soule was ordained, both deacon and elder, by Bishop Richard Whatcoat.

He was appointed a presiding elder at the age of 23, placed in charge of the state of Maine.

In 1820, he was elected bishop, but declined consecration because the General Conference had adopted a policy he could not approve.