In the revolutionary years from 1845 to 1850 young Parker as a local preacher and temperance orator gained a reputation for vigorous utterance.
He was influenced by Thomas Cooper, the Chartist, and Edward Miall, the Liberationist, and was much associated with Joseph Cowen, afterwards MP for Newcastle upon Tyne.
Horsley was about ten miles from Hexham, and he became acquainted with the Nesbitts through his preaching there, and Mr Nesbitt, a trustee and deacon of Horsley Congregational Church was especially interested in the young preacher, who, on Sunday nights, brought them the news of the town and slept in a "snug little chamber" in the old farmhouse.
However, when Horsley Congregational Church was rebuilt, Dr. Parker presented a beautiful stained glass window, bearing the following inscription: "In ever loving memory of Ann Nesbitt, for twelve years the devoted wife of Joseph Parker, Minister of the City Temple, London, this window is reverently and gratefully erected by the man whose life she did so much to mould".
His stimulating and original sermons, delivered with a ready command of vigorous English, made him one of the best known personalities of his time.
[4] On 22 December 1864, Parker married Emma Jane, daughter of Andrew Common JP, banker, of Sunderland.
He did not follow outlines or list his points, but spoke extemporaneously, inspired by his view of the spirit and attitude behind his Scripture text.
Charles Spurgeon praised his originality, writing, "Dr. Parker's track is his own and the jewels he lets fall in his progress are from his own casket.
"[10] Among his biographers, Margaret Bywater called him "the most outstanding preacher of his time",[11] and Angus Watson wrote that "no one had ever spoken like him.
"[12] Another writer and pastor, Ian Maclaren, offered the following tribute: "Dr. Parker occupies a lonely place among the preachers of our day.