In the Holy Catechism, Saint Nektarios of Aegina provides a comprehensive overview of Eastern Orthodox doctrine and practice. It is designed to educate young Christians, baptismal candidates, and newcomers to the faith, as well as edify and inform more mature believers. Saint Nektarios' unique blend of scholarly erudition and pastoral counsel makes this a challenging and engaging introduction to the history and teachings of the Church.

The is Parts 1 and 2 combined.