Bishop Petrelli invited different Roman Catholic religious institutes to come to his diocese and help minister to the spiritual needs of the faithful. He also conceived the building of a seminary in the diocese. In June 1914 a diocesan seminary was built in Bauan, which was later transferred to San Pablo in Laguna. This initiative of the first bishop was continued by the next bishop, Alfredo Verzosa, the diocese's first Filipino bishop, who served a long term from 1916 to 1950. He invited priests from the Society of St. Vincent de Paul to help in the administration of the new seminary.