Returning to Ireland in 1758 he married his cousin, Jane Carlile of Newry, and in 1759 was ordained minister of the non-subscribing presbyterians at Antrim.
In November 1764 he became minister of First Armagh, in connection with the general synod, his successor at Antrim being William Bryson.
An unpublished pamphlet, addressed to Hussey Burgh in the same year, proposed a scheme for a northern university which, though considered by several governments, ultimately failed through Henry Grattan's disapproval.
But the influence of Lord Hillsborough went strongly against the general synod, for political reasons; by his advice a grant of regium donum (500l.
In 1786 he entered into controversy with Richard Woodward, bishop of Cloyne, who had maintained that none but episcopalians could be loyal to the constitution.
Applying in 1788 for the post of synod's agent for the regium donum, he was defeated by a large majority in favour of Robert Black.
On 14 September 1789 he resigned Armagh, and spent the remainder of his days in charge of the small flock at Clonmel, Tipperary.