VATICAN CITY (AP) — Celebrating Mass with poor people, Pope Francis is denouncing "indifference" as a great sin.

St. Peter's Basilica on Sunday was filled with poor people as well as prelates as the Catholic church marked its first "World Day for the Poor."

Francis decried those who contend that poverty's "not my business, it's society's fault."

He told faithful that a lifetime of "doing nothing wrong isn't enough" and called helping the world's poor the "passport for Paradise." He said people will enter Heaven "not for what you have, but for what you give" to the needy.

Francis has invited 1,200 poor people to join him for a lunch of pasta, veal and dessert in a Vatican auditorium after Mass. Paying attention to those on society's margins is a hallmark of his papacy.