praying for the dead

The Catholic customs of praying for the souls of the dead, praying to the saints who have gone before us in earthly life, and of venerating relics are based primarily in the church’s long-standing tradition and theology rather than explicit scriptural “prooftexts.” However, the Bible does indeed allude to these practices.

Where does the tradition of praying for the dead come from, and do all popes have a number behind their name?

During the month of November, the Catholic Church asks the faithful to spend 30 days praying for the dead.