He studied at the University of Poznań and the seminary in the same city before being ordained to the priesthood by Bishop Antoni Laubtiza on 29 May 1926.

He following a period of pastoral work in Gniezno, Filipiak went to Rome to study at the Pontifical Roman Athenaeum S. Apollinare and the Institute Utriusque Iuris (from where he obtained a doctorate in canon and civil law on 13 April 1935).

Filipiak was jailed in Nazi prisons for a year and then made a member of the archdiocesan tribunal of Gniezno in 1945.

Filipiak was made an honorary canon of the cathedral chapter of Gniezno on 15 October 1947, and of Poznań on 8 September 1958.

He received his episcopal consecration on the following 14 May from Cardinal Pericle Felici, with Archbishop Antoni Baraniak and Bishop Andrzej Deskur serving as co-consecrators, in the church of Sant'Anselmo all'Aventino.