By Mark Abrams

PHILADELPHIA (CBS) — The World Meeting of Families Congress is set to begin in Philadelphia a few days ahead of the visit of and the spiritual father of the event, Pope Francis.

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The largest Roman Catholic religious convention of its kind convenes on Tuesday at the Pennsylvania Convention Center with more than 17,000 people from countries around the globe registered to take part.

Philadelphia Archbishop Charles Chaput is the host for the Vatican-sponsored event which concludes with the arrival of the pope himself at the end of the week.

Chaput says he’s looking forward to the pope’s Mass in the Cathedral Basilica of Saints Peter and Paul, his speech in front of Independence Hall on Saturday, as well as the Festival of Families and the open-air papal Mass on the Ben Franklin Parkway on Sunday. But the archbishop admits he’s trying to keep his focus on the events a day at a time.

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“I haven’t allowed myself to focus very much yet on what it’s going to be like those last two days,” Chaput says. “My full-time and attention is focused on how we get from here to there. I think that once Tuesday comes and we begin the World Meeting of Families, I’ll begin to imagine what it’s like.”

But Chaput concedes arrangements for Sunday’s papal Mass and the safe departure of the pope are weighing on his mind.

“The final Mass when we hope a million people come to join him will be a great moment of prayer,” he says, “and then sending him back home with a wonderful experience of the United States, as well as our own community here in Philadelphia.”

Chaput says he’s concerned the pope might be tired by the time he gets here because of the stops in Cuba, Washington D.C. and New York. He says he wants Pope Francis to feel relaxed and experience the warmth and love from the city of America’s birth.

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