Charles did not leave Sparkford until he resigned all his curacies in June 1783, and returned to Wales, marrying (on 20 August) Sarah Jones of Bala, the orphan of a flourishing shopkeeper.

[2] Charles had been influenced by the great revival movement in Wales, and at the age of seventeen had been converted by a sermon of Daniel Rowland.

This was enough to make him unpopular with many of the Welsh clergy, and being denied the privilege of preaching for nothing at two churches, he helped his old Oxford friend John Mayor, now vicar of Shawbury, Shropshire, from October until 11 January 1784.

First one man was trained for the work by Charles himself, then he was sent to a district for six months, where he taught the children and young people reading and Christian principles.

A powerful revival broke out at Bala in the autumn of 1791, and his account of it in letters to correspondents, sent without his knowledge to magazines, kindled a similar fire at Huntly.

John Thornton and Thomas Scott helped him to secure supplies from the Society for the Promotion of Christian Knowledge from 1787 to 1789, when the stock became all but exhausted.

[4] It was in 1800 that a 15-year-old girl, Mary Jones, walked 26 miles from her home to obtain one of his Bibles, and she was seen as a shining example of religious devotion, an inspiration to Charles and his colleagues.

[citation needed] In 1800, when a frostbitten thumb gave him great pain and much fear for his life, his friend, Philip Oliver of Chester, died, leaving him director and one of three trustees over his chapel at Boughton; and this added much to his anxiety.

[4] The London Hibernian Society asked him to accompany David Bogue, Joseph Hughes, and Samuel Mills to Ireland in August 1807, to report on the state of Protestant religion in the country.

[4] Charles died, "worn down by his activities" according to biographer Edwin Welch, in October 1814, nine days before his 59th birthday, and was buried at nearby Llanycil.

All his work received very small remuneration; the family was maintained by the profits of a business managed by Mrs Charles a keen, active and good woman.