History is always important, sorry for the wall of text.
About the Ulster Covenant
The archive of the Ulster Unionist Council, held by PRONI, contains just under half a million original signatures and addresses of the men and women who signed the Ulster Covenant or corresponding women's Declaration on 28th September 1912.
The Ulster Covenant was a response to the latest Home Rule Bill to be proposed in Westminster to settle the long running ‘Irish Question’ by giving Ireland a limited measure of local autonomy. The first two bills had been rejected by Parliament in 1886 and 1893. In June 1892 a demonstration in Belfast, the Ulster Convention, was chaired by the Duke of Abercorn and attracted 20,000 opponents to Home Rule.
By 1912, Liberal British Prime Minister Herbert Asquith had proposed a third Home Rule Bill. Whilst it dragged its way through the Commons, the Ulster Unionists made preparations for active resistance. In January 1912 they had begun to raise and openly train a military force which became known as the Ulster Volunteers.
Back at Westminster, Unionists put up fierce opposition to each stage of the Home Rule Bill, and the third reading was not carried until January 1913, after which the Bill received its expected defeat in the House of Lords. The outbreak of World War I then halted further progress.
Sir Edward Carson (Leader of the Irish unionist Party) and James Craig (the Unionist MP for East Down) appreciated the importance of maintaining order and discipline among their followers. A solemn and binding oath to resist Home Rule that could be signed by the men of Ulster was one means by which Carson and Craig believed they could maintain cohesion in their organisation. This was as much for propaganda value as for any other reason — to convince public opinion at home and abroad of the solidarity, determination and self-control of Unionists.
After much consideration as to the wording, it was suggested that a model might be the Scottish National Covenant of 1638 which was a protest against the King's right to determine how the Scottish Church should be governed. A special commission was appointed to adapt the wording to suit Ulster's circumstances, when it was realised that a shorter and plainer-English version would be more suitable. This was drafted by Thomas Sinclair, a Belfast merchant and leader of the Ulster Liberal Unionism that had broken with the Liberal party on the Home Rule issue.
When the Covenant was submitted to the Protestant Churches, a crucial change and note of caution was introduced. The Presbyterians advised that the obligations on signatories should be confined to the present crisis as no one could predict what circumstances might arise in the future.