[1] John Abernethy Senior accompanied Patrick Adair on a deputation from the general committee of Ulster presbyterians, who presented a congratulatory address to William III in London 1689, and obtained from the king a letter (9 November 1689) recommending their case to Duke Schomberg.
[2] In his thirteenth year, John Abernethy Junior entered the University of Glasgow, and on concluding his course there went on to Edinburgh, where he soon moved into the most cultured circles.
Abernethy and his associates sowed the seeds of the struggle (1821–1840) in which, under the leadership of Dr Henry Cooke, the Arian and Socinian elements of the Irish Presbyterian Church were thrown out.
[4] However, Dr Henry Cooke stated that Arianism "made very considerable progress under the patronage of high names, as Abernethy, the author of a very excellent work upon the Attributes, who gave it a great deal of eclat".
His stand was: against all laws that, upon account of mere differences of religious opinions and forms of worship, excluded men of integrity and ability from serving their country.