Worship

Idols were generally worshiped, the earliest authentic document that mentions idols is St. Patrick's Confession in which the great apostle himself speaks of some Scots (i.e Irish) who up to that time "had worshiped only idols and abdominations". In the same document as in many other ancient authorities, the practise of idol-worship is mentioned as a thing well known among the Irish, and the idols in various parts of the country was an important part of St. Patrick's life-work.

There was an great idol called Cromm Cruach that was covered all over with gold and silver, in Magh Slecht "the plain of prostrations" near the present village of Ballymagauran in the county Cavan. It was surrounded by twelve lesser idols that was coverd with bronze. In the most ancient books Cromm Cruach is mentioned as a chief idol of the whole country, and as being "until the coming of Patrick, the god of every folk that colonised Ireland".

In a very old legend found in Dinnsenchus in the book of Leinster it was told that many centuries before the christian era, King Tigrumas [Teernmas] and crowds of his people were destroyed in some mysterious way, as they were worshipping it on Samain eve - the eve of the first november.

Pillar stones were worshipped in other parts of Ireland, there was adoration of pillar-stones in Ireland a statement which you can find in other old authorities. In the Brehon Laws one of the objects used for marking the boundaries of land is stated to be "a stone of worship". This interesting record at once connect the Irish custom with the Roman worship of the god Terminus, which god was merely a pillar-stone placed standing in the ground to mark the boundary of two adjacent properties, exactly as in Ireland. Even to this day some of these old idols or oracle-stones are known and the memories of the rites performed at them is preserved in popular legend.

The Irish like the Scottish Highlanders had an idol called Bel [Baill] whose worship was celebrated with fire-ceremonies. There was a great meeting held at Ushnagh (in present Westmeath) every year on the first of may, when two fires were kindled in Bel's name with solemn incantations by the druids, and cattle were driven between the fires to protect them against the dieseases of the coming year.
On this occation moreover the young of cattle were offered to the idol. These pagan cermonies were practised on May Day all through Ireland, in imitation of those at Ushnagh and were continumed down to late times. The Irish like the continetal nations of the middle ages paid great reverence to their arms, espacially swords amounting somethimes to down-right worship, witch accounts for the custom of swearing by them.
This oath wich was very usual in Ireland was quite as binding asthat by the elements.
The reson is given in "The sick bed of Cuculainn", becouse demons were accustomed to speak to them from their arms and hence it was that an oath by their arms was inviolable.