The auxiliary bishop of Dublin, James Moriarty was installed as the bishop of the diocese of Kildare and Leighlin at the weekend.
Taoiseach Bertie Ahern and Justice Minister Michael McDowell joined representatives from the diocese at the Cathedral of the Assumption in Carlow on Saturday.
The new bishop said that spreading the Christian word was his main priority.
“The promotion of the ideals of the gospel of Jesus Christ continues to be the urgent and vital call of all Christian people,” he said.
He succeeds Bishop Laurence Ryan who retired after serving in the job since 1987.
The hierarchy, priests from both Dublin, Kildare and Leighlin dioceses, local Church of Ireland bishops, Richard Clarke and John Neill, and former Archbishop of Dublin,Walton Empey also attended.
Bishop Moriarty received a warm welcome to the cathedral where he was asked to accept his new role by outgoing bishop, Laurence Ryan.
The Papal Nuncio Giueseppe Lazzarotto presented bishop Moriarty with his letter of appointment.
In his homily at the mass Mgr Brendan Byrne described bishop Moriarty as “a man of faith and conviction who has exercised great pastoral care whether as University Chaplain, parish priest or Bishop.”
He said that modern day society means it’s essential that lay people, priests and bishops work together to ensure “Christianity captures the imagination of our culture’.
Mgr Byrne congratulated Bishop Ryan on his dedicated ministry of the past 14 years and wished him well in his retirement.
The new bishop said he is looking forward to meeting the people of the diocese in the coming weeks.