McGrath travelled widely throughout Northern Ireland preaching his religious message, which included hard-line
Ulster loyalist principles. McGrath claimed that
Northern Ireland was on the verge of chaos and blamed it on the
Provisional Irish Republican Army's supposed turn to
communism, which he saw as the enemy of
Christianity. According to the
Royal Ulster Constabulary (RUC), as part of his virulent
anti-communism, McGrath made contact with clandestine religious groups in Eastern Europe and smuggled in Bibles and religious tracts for their use. His message was also highly
anti-Catholic, arguing for instance that the Pope had all nuns and priests as part of his private army and that the
Society of Jesus was deliberately destroying
Ulster Protestant culture. McGrath argued that until the 12th century Ireland had adhered to a local form of
Celtic Christianity until
Pope Adrian IV had decreed that
Henry II of England should invade and force out the native church in favour of what McGrath portrayed as the decadent Roman church. On this basis McGrath added an all-Ireland dimension to his thinking that was at odds with the wider political circles in which he was to move. By the mid-1960s some of McGrath's closest followers, including Garland, had begun to meet at his 15 Wellington Park base, a well-to-do area of Belfast (McGrath having shifted operations there in 1960), along with several senior
Orangemen in a group known as the "Cell".
Clifford Smyth also became part of this cell and grew close to McGrath, stating that at the time he was attracted to his strong anti-Catholic rhetoric. The cell spearheaded a campaign of speeches to
Protestant audiences, more political than religious in tone than McGrath's earlier talks, encouraging
unionists and loyalists to turn away from the moderate
Terence O'Neill and to lend their support to his most vocal political opponent
Ian Paisley. McGrath and Paisley differed over the latter's regular attacks on mainstream Protestant churches for their liberalism but McGrath admired Paisley's mobilisation of men and became involved in his
Ulster Constitution Defence Committee. Despite their political collaboration, McGrath was not a member of Paisley's
Free Presbyterian Church of Ulster although two of his children were married in Paisley's Martyrs Memorial Church. In 1966, McGrath produced a series of leaflets in defence of
Gusty Spence, the leader of the recently formed
Ulster Volunteer Force (UVF), who was on remand for the murder of two young Catholics. McGrath's leaflets alleged that both victims were active communists and claimed that the UVF had been established by members of the
Official Unionist Party, with
Jim Kilfedder named specifically as being involved. The leaflet was an attempt to both smear the mainstream unionist party and to deflect criticism from Paisley, who was at the centre of speculation linking him with the UVF. McGrath was not a member of any established branch of religion, with his evangelical group being independent, something
Fraser Agnew put down to McGrath's unwillingness to be constrained by the rules of any organisation. McGrath was secretary of the Christian Fellowship and Irish Emancipation Crusade (CFIEC) when he appeared with Paisley at a rally in July 1966: this organisation, based in Wellington Park, was a Tara front in which his son Worthington was involved. A CFIEC pamphlet on "Romanism" illustrates McGrath’s attitude to Catholicism: "an age-old threat to the fortunes and liberties of mankind". These publications also reflected its leader’s curious fixation with Ireland as opposed to Ulster or Great Britain, with headlines "For God & Ireland" and "A Nation Once Again" and imagery including a map of Ireland with no border and the Irish phrase "
náisiún ar ais (a nation once again)". ==Tara and paramilitary links==