Wars have been waged across Europe and battles are still being fought today over matters of theological disputation, as manifest by the collision between extreme Muslims and the western world.
For centuries, Ireland has been riven by deep-seated divisions between the Catholic and Protestant churches. Therefore, when representatives of the communities come together in a spirit of unity it ought to be a cause of celebration. However, despite advances in the ecumenical field, the controversy raging following the concelebration of Easter Mass by Catholic priests and a Church of Ireland clergyman in Drogheda, has emphatically demonstrated that the boundaries remain as sharply defined as ever. What began, perhaps naively, as an inclusive eucharistic celebration of the 1916 Rising, involving a congregation of one thousand parishioners drawn from both churches, is believed to be the first concelebration of its kind since the Reformation was initiated by Martin Luther in 1517.
Doubtless, the far-reaching reverberations of this ground-breaking event will be felt from Rome to Canterbury and so it was not surprising that the primates of both the Catholic and Protestant churches in Ireland should launch separate probes into the circumstances surrounding such a remarkable event.
Equally unsurprising, Fr Iggy O'Donovan, the priest in the eye of the storm, who has publicly assumed responsibility for inviting the Rev Michael Graham to join in celebrating the Mass, has apparently embarked on a week-long retreat.
Before doing so, however, he admitted on the Tom McGurk show, in a classic understatement, that he thought there "might be some reaction". If anything, he was entering a minefield.
By coincidence, Fr O'Donovan too is an Augustinian, as was Martin Luther, but, as he explained yesterday, his intention was to unite parishioners in a spirit of religious unity. The former prior argues that it is a tenet of his faith that the Rev Graham could concelebrate Mass with him. What they shared in common, he says, was that both accepted the presence of Christ in the eucharist and in the congregation. In his considered opinion, much of the theological and philosophical arguments surrounding the doctrine of transubstantiation came down to hair-splitting and quibbling, a view shared by many.
The fallout inevitably brings to mind the furore that erupted in 1997 when President Mary McAleese received communion at Christ Church Cathedral in Dublin. At the time, the Archbishop of Dublin, Cardinal Desmond Connell, sparked controversy and angered Church of Ireland bishops when he questioned the bona fides of the Anglican community.
In a welcome change of atmosphere, a less confrontational approach has been taken in the current controversy. The Catholic Primate, Archbishop Sean Brady has warned that holding such a Mass involved a 'real danger of causing widespread confusion raising false hopes and creating situations that are open to misunderstandings and manipulation'.
In similar language, the Church of Ireland Primate, Dr Robin Eames, emphasised that such occasions, though well-intentioned, might well be misunderstood.
All too often, the troubles that arise in the field of ecumenism stem from an implicit failure to recognise and respect fundamental dividing principles. There can, however, be little doubt the Mass in Drogheda was celebrated in an exceptional spirit of unity and a true sense of reconciliation by both communities.
In the ensuing controversy, it would indeed be sad if, as Fr O'Donovan succinctly put it, the eucharist was to become a symbol of division and discord.