More than 90 per cent of the 3,200 primary schools in the Republic are under the patronage of the Catholic Church.
They use the Alive-O religious education programme, a series of books based on a syllabus devised by the Irish bishops in the 1970s.
Many Protestant schools use an amended version of the Alive-O series, altered to reflect the values of the Church of Ireland, Methodist or Presbyterian faiths.
Educate Together schools have their own programme of multi-denominational religious instruction that covers all major belief systems.
The Alive-O series comprises books, posters and CDs, and emphasises prayer, human rights, devotion through music, Marian devotion, Bible reading and sacrament preparation.
The books are child friendly, using aids such as "Little Beings" as a description of conscience, "justice games" to teach about poverty and injustice, and featuring "modern day prophets", who work to alleviate poverty. According to primary teacher Sr Anne Nealon, "Prayer, reading and reflection are at the core of individual lessons. Alive-O encourages and promotes inclusion in all aspects of life".
Teacher trainees in the Colleges of Education are offered a diploma in religious education alongside their basic training, which they must complete to work in Catholic schools.
The first State-run primary school will open at Diswellstown in Dublin 15 next year.