[1] He was born in Barbados into a slave-owning family, the son of Henry Coulthurst, and became joint owner of a plantation in Demerara.
[6] He is mentioned by Thomas Clarkson as one of those who came forward to help the abolitionist committee in the period from 1788 of agitation against the Atlantic slave trade.
Theophilus Lindsey in December 1788 noted that one of the leaflets was a reply to a sermon by Coulthurst that Frend had attended.
The fifth leaflet, dated 18 February 1789, related to the Johannine Comma, and in it Frend cited in support Richard Porson ("Cantabrigiensis"), from his controversy with George Travis.
[10][11] Lindsey also commented that Coulthurst was "one of those that are reckoned Methodists" in various Cambridge colleges, which in the language of the time implied an evangelical.
[12] Coulthurst was appointed vicar of Halifax, Yorkshire in 1790, with the advantage of support from William Pitt the younger.
[13] In 1793 Wilberforce arranged for Coulthurst to preach in Somerset, as reported by Hannah More who was then living near Wrington, to Sir Charles Middleton.
[14] Describing in 1795 his parish as containing 70,000 people and being as large as Rutland, Coulthurst expressed concern that no magistrate was active there.
[1] In 1796 he preached a noted university sermon, backing the measures against subversion taken by the administration of William Pitt, one of a number of evangelicals taking a loyalist line at the time.
[21] That church was built at Coulthurst's own expense, and he also contributed to the upkeep of a number of the chapels in his parish, building one more.
[1][27] William Willmott, a Halifax curate, preached a memorial sermon in the Parish Church on 21 December.
Coulthurst and his heirs could rent out the pews and galleries, and sell 20% of the land attached as burying ground, at prices regulated by the Archbishop of York.