Mair was one of two further ministers (the other being
Ralph Erskine of
Dunfermline) who in 1737 joined the "four seceders", the original four ministers of the
First Secession of 1733. He had protested against their removal from office in 1733, and his election by the
Consistory to minister of the Scottish Church in
Rotterdam on 21 August 1736 had been quashed by magistrates on 24 November 1736, after it had been falsely reported to them by the British envoy at
The Hague (according to letters sent by Robert Storie from Rotterdam in 1736) that he objected to patronage and was an
Antinomian.
Ebenezer Erskine had written to Rotterdam in support of Mair, as had minister Neil MacVicar (who denounced the charge of Antinomianism as being "as far removed from [Mair] as darkness from light") and minister William Gusthart. Nonetheless, Mair was not appointed to the church in Rotterdam. Instead, on 16 February 1737, he left the Church, and two days later joined the Associate Presbytery of the Secession. It was he who read the Secession's
Declinature on 17 May 1739 to the
Assembly of the Church of Scotland. As an objector to the
Burgess Oath, he became the moderator of the Associate Presbytery's Synod, picking the Anti-Burgher side when it later split in the Breach of 1747. In 1740, he, alongside the other secessionist ministers, were all formally deposed from office by the Assembly. When Mair was deposed, he and his congregation were prevented from using the parish church building. Early accounts state that they worshipped in the open air until 1742, at which point they were able to begin using a church building that they had themselves built in
Milnathort, named the "Muckle Kirk". Small contradicts them, pointing out that contrary to accounts that Mair and his congregation were evicted in 1740, they in fact continued to use the parish church building until 1742, when the General Assembly's attention became drawn to this and it empowered the Presbytery of Dumfermline to enforce their deposition order and "to crave the assistance of the civil power if necessary". Mair himself recorded in his diary that he lost his stipend and was supported instead by a collection that was taken amongst his parishioners. The Muckle Kirk was so named because in addition to it having seating inside for 1200 people (another point where Small, on the basis of what is actually recorded in the manager's books, corrects the earlier authorities who had claimed 2000 people), its hillside location presented a natural amphitheatre at the rear of the building, allowing folding doors to the rear to open out for more congregants to attend services outside. It was later to be known as the Orwell Free Kirk and stood in what is now Viewfar Road. When the congregation shrank in later years, after the congregants from
Kinross, Milnathort, and
Balgedie withdrew from attendance, it was demolished to be replaced in 1821 by a smaller church on the same site that seated just 550 people. ==Ejection and later life==