Young adults should step away from consumerism and cynicism as part of their important role in bringing forward their desire for justice and a better world, said the Catholic Archbishop of Dublin, Dr Diarmuid Martin.
At his first Midnight Mass at the Pro-Cathedral in Dublin, Dr Martin urged young people to "Step out of conformism, then, and bring the newness of the message of Jesus to the world where we live."
"The message of Christmas can shake us out of the superficial conformism of the consumerist world. I have watched in the past days at different carol services the faces of children as they listen in wonder at the beautiful and moving story of the birth of Jesus."
He urged people, even the most sophisticated, to not be ashamed to allow the "innocence and simplicity of a child to reappear in our hearts".
This simplicity, wonder and sheer goodness are precisely what a world tempted by cynicism, scepticism and indifference needs."
He asked the congregation to remember the Irish troops stationed in Liberia and elsewhere, adding that rarely "has there been such a united longing for peace, shared by young and old, across all the political and religious traditions on our Ireland".
The Catholic Primate of All Ireland, Archbishop Sean Brady, said it would be a tragedy if Christ's birthday were forgotten today.
And in his Christmas message, the Church of Ireland Archbishop of Dublin Dr John Neill said Irish people must build bridges of understanding with immigrants to avoid a society of violence and ghettos.
Dr Neill, who will be giving a sermon at Christ Church Cathedral in Dublin today, said people must communicate with those who are coming to our shores "with little or nothing".