[1] He entered divinity classes of Glasgow College in December 1644, and was ordained at Cairncastle, County Antrim, 7 May 1646, by the "army presbytery" constituted in Carrickfergus 10 June 1642 by the chaplains of the Scottish regiments in Ulster.
[1] Adair was one of eight ministers summoned to the general convention at Dublin, February 1660, at a time when there were hopes of a presbyterian establishment, soon dispelled by the restoration of Charles II.
Jeremy Taylor, consecrated bishop of Down and Connor 27 January 1661, summoned the presbyterian ministers to his visitation, and on their not attending declared their churches vacant.
After the defeat of the Scottish covenanters at Bothwell Brig (June 1679) fresh severities were inflicted on the Ulster presbyterians; their meeting-houses were closed and their presbytery meetings held secretly by night.
James II's Declaration of Indulgence (1687) gave them renewed liberty, which was confirmed by the accession of William III, though there was no Irish toleration act till 1719.
[2] Late in life he drew up A True Narrative of the Rise and Progress of the Presbyterian Government in the North of Ireland, extending from 1623 to 1670, which it is to be regretted that he did not finish.
He married first his cousin Jean (died 1675), second daughter of Sir Robert Adair of Ballymena; second, a widow, Elizabeth Anderson (née Martin).