A strong Calvinist and a zealous Evangelical, he was responsible for bringing Howel Harris to preach for the first time in Monmouthshire in March and April 1738, at Ebwy Fawr (probably in Ty-llwyn), on which occasions the subsequent leaders of Methodism in Monmouthshire were converted, notably John Powell (3, q.v.) and Morgan John Lewis (q.v.).

Though friendly to Harris, Jones feared that the progress of Methodism among Nonconformists might draw many of them to the Established Church, as Harris desired, in hope of reforming it from within. He therefore actively encouraged some societies, as at Devynnock and Neath, to form themselves into Independent churches, and this caused differences between Harris and himself. But the strong Calvinistic views of both were a common bond to the day of Harris's death. Edmund Jones's piety and evangelical zeal were admired both by Whitefield and the countess of Huntingdon, and he was always welcome at the latter's Trevecka college.

He was married but childless; his wife Mary (b. in 1696) d. 1 Aug. 1770. Their married life was very happy, but it is a baseless legend that Whitefield decided to find a wife after seeing their happy state. Jones was always poor, but always generous. He was known to have given his greatcoat on one occasion and his shirt on another to poorer people whom he met on his travels.

An indefatigable preacher, he itinerated frequently in Wales and in England. In 1782 he travelled 400 miles on foot in North Wales, preaching twice daily; even in 1789 when 87 years of age, he preached 405 times. He was not, however, a popular preacher. Apart from various volumes of sermons he is best known for his Historical Account of the Parish of Aberystruth, 1779, a competent piece of work which requires several readings for the right appreciation of many of the facts incidentally or implicitly referred to in it, and also his Relations of Apparitions in Wales, 1780, which is a farrago of the most astonishing superstitions, in all of which he firmly believed; hence he was frequently referred to as ‘Yr Hen Broffwyd’ (The Old Prophet). His diaries for nine years survive at the N.L.W., having been rescued from use as wrapping paper in a Pontypool shop shortly after his death.

Edmund Jones was a man of dual personality — fearless in preaching and in founding new churches, a zealous evangelical and a firm Calvinist, yet frightened of apparitions and terrified by bad omens. He was devoid of poetic feeling but an incessant recorder and chronicler of religious developments, and his name recurs in almost every work dealing with 18th cent. Wales. An excellent article on him appeared in Yr Adolygydd, 1850, by Evan Jones (Ieuan Gwynedd), reprinted later in his collected works.