Msgr. Kupke, co-host of the popular podcast Coffee with Kupke, was ordained a priest for the Diocese of Paterson in 1973 and was named a Prelate of Honor (Monsignor) by Pope John Paul II in 1998. A respected church historian, he has served as Archivist of the Diocese of Paterson since 1976, following archival studies at New York University. Over the years, he has held numerous pastoral assignments, including Parochial Vicar at St. Philip the Apostle in Clifton, St. Pius X in Montville, St. Peter the Apostle in Parsippany, Administrator of St. Thomas of Aquin in Ogdensburg, and Pastor of Holy Family in Florham Park and St. Anthony in Hawthorne.

Msgr. Kupke has taught widely in the areas of Church history, including the Medieval Church, the Counter-Reformation, and Vatican II. He has also taught many courses at St. Paul Inside the Walls, most notably helping to form candidates for the permanent diaconate. He is the author of Living Stones: A History of the Catholic Church in the Diocese of Paterson and has contributed to major reference works such as The New Catholic Encyclopedia and The Encyclopedia of American Catholic History. A member of several historical associations, he also writes regularly on New Jersey Catholic history.