He was ordained into the priesthood by the Bishop of Eichstätt, and said his first Holy Mass on Pentecost Sunday, June 12, 1639 in the Church of Our Lady of Victory, at Ingolstadt.

In the spring of 1655, at the invitation of Archbishop Johann Philipp von Schönborn, he went to Mainz where he was soon appointed pastor at Bingen on the Rhine, and in 1657, dean of the district of Algesheim.

Bartholomew Holzhauser founded the Bartholomites, called United Brethren or officially Institutum clericorum sæcularium in communi viventium, also receiving the designation Communists in the aftermath of the Thirty Years War in Europe.

The members of the secular congregation were expected to live in the seminaries, or in groups of two or three in the parishes, and to follow a set routine of daily prayers and exercises.

At Tittmoning, encouraged by John Christopher von Lichtenstein, the Bishop of Chiemsee, a suffragan and principal adviser of the Archbishop of Salzburg, he had made a good beginning.

Holzhauser was a visionary, and made his visions public by presenting them in 1646 to Emperor Ferdinand III and to Duke Maximilian I, Elector of Bavaria.

He interpreted the book of the Apocalypse as follows: The seven stars and the seven candlesticks seen by St John signify seven periods of the history of the Church, from its foundation to its consummation at the final judgment.

To these periods correspond the seven churches of Asia Minor, the seven days of the Mosaic record of creation, the seven ages before Christ, and the seven gifts of the Holy Ghost.

The central features of this apocalyptic commentary concerned the strong ruler, or the Grand Monarch, and the Holy Pope, a favorite subject of medieval prophecy, as well as the division of church history into seven periods.