Archbishop Charles Chaput said his goodbyes Sunday night to a flock that filled the Basilica of the Immaculate Conception.
He summoned people in from the foyer to fill the aisles and sit at the steps of the sanctuary and warned them that he might preach for an hour.
"Instead of saying goodbye," he said to his parishioners, "why don't we just listen to the word of God."
Chaput gave his final Mass before leaving Denver to shepherd the 1.5-million-member Archdiocese of Philadelphia, where he is to be installed on Sept. 8. He was appointed by Pope Benedict XVI in July to the task of restoring an archdiocese rocked by a sexual-abuse scandal.
Sunday night, Chaput was preceded in the ornate basilica by AmericanIndian drummers.
A member of the Prairie Band Potowatomi tribe of his native Kansas, Chaput is only the second American Indian to be ordained a bishop in the United States and the first American Indian archbishop.
His replacement in Denver has not yet been named.
The 66-year-old Chaput has served the Denver archdiocese for 14 years, forging a national reputation for his conservative, orthodox Catholicism.
He has taken high-profile stances against gay marriage and abortion, while championing social justice, immigration reform and cultural diversity.
In the process, Chaput has earned praise and devotion from some and criticism from others.
No critics could be found in his presence Sunday night.
"He literally just held my hand and prayed together that the Lord will provide me with a home someday," homeless parishioner Chris Orchard told 9News Sunday night.
Anna Marie Larsen considered the loss.
"Denver is really losing an incredible person and an incredible leader for our church," she told the station.