Pope Francis is making good on his insistance that the Catholic Church welcome all faithful — not just those who obey church teaching perfectly. He'll marry 20 couples this weekend, including some who already live together and those with children, technically a sin in the eyes of the church.

Sunday's mass wedding in St. Peter's Basilica was timed to coincide with the start of a major two-year study by the Vatican of a host of issues affecting family life, including premarital sex, contraception and divorce.

The diocese of Rome, which is organizing the ceremony, said the couples range in age from those in their mid-20s to those in their 50s and include "those who are already living together, those who already have children, those who met in church."