#4 (below) reproduces the Symbol of Faith of the XI Council of Toledo, 675, when the Filioque was not defined.

The act of faith shows how just it is to say that God chose Bruno, a man of eminent holiness based on the faith of the Church, to restore to the contemplative life the glory of its original purity.

[1] I firmly believe in the Father, the Son and the Holy Spirit: the Father unbegotten, the Son only begotten, the Holy Spirit proceeding from the one and the other; and I believe that these three Persons are one only God.

[2] I believe that the same Son of God was conceived of the Holy Spirit of the Virgin Mary. I believe that she was a most chaste Virgin before the birth, a virgin in the birth, and after the birth she remained a virgin forever. I believe that the same Son of God was conceived among men as a true man without sin. I believe that the same Son was taken captive out of envy by unbelieving Jews, treated abusively, unjustly bound, spat upon, scourged, died and was buried. He descended into hell that he might free from there his own who were held captive. He descended for our redemption, and rose again, ascended into heaven; from there he shall come to judge the living and the dead.

[3] I believe in the sacraments which the Catholic Church believes and venerates, and expressly that what is consecrated on the altar is the true body, true flesh and true blood of Our Lord Jesus Christ, which we receive for the remission of our sins and for the hope of eternal salvation. I believe in the resurrection of the flesh and in life everlasting. Amen.

[4] I confess and I believe the holy and unspeakable Trinity, Father, Son and Holy Spirit, one natural God, of one substance, one nature, one majesty and power. We profess that the Father is not begotten, not created, but unbegotten. The Father takes his origin from no one; from him the Son has received his origin and the Holy Spirit his procession. He is therefore the source and origin of the whole Godhead. He himself in his own unspeakable essence is the Father, who in an unspeakable way has begotten the Son of his substance. Yet he did not beget something different from what he himself is: God has begotten God, light has begotten light. From him, therefore, is "all fatherhood in heaven and on earth". Amen.