Benedict XVI’s decision to retire and live a life dedicated to prayer is an important lesson for the world’s priests, Pope Francis has said.

In retirement, Benedict XVI shows “in an even clearer way” the core of priestly ministry is a life fully immersed in God, something “that deacons, priests and bishops must never forget”, Pope Francis writes in the preface to a new book by his predecessor.

“The primary and most important service is not the management of ‘day-to-day business’, but praying for others without interruption, body and soul, exactly like the Pope Emeritus does today – constantly immersed in God.”