Updated

Pope Francis has written his first encyclical, and it's on faith.

The Vatican said Monday that "Light of Faith" will be released on Friday.

Retired Pope Benedict XVI had planned to issue a final encyclical on faith, but retired before he had time to finish it.

The Vatican has long said Francis would likely take elements of Benedict's draft and make them his own.

An encyclical is the most authoritative teaching a pope can issue. Benedict issued three during his nearly eight-year pontificate, on charity, love and hope.