The history of his early life is unknown, but he was a Roman Catholic priest who had been deprived of his office by the Church hierarchy for teaching unorthodox doctrine.
Peter admitted the doctrinal authority of the Gospels in their literal interpretation but considered the other New Testament writings to be valueless, as he doubted their apostolic origin.
'"[6] That idea ran counter to the medieval Church's teaching, particularly in the Latin West, following the theology of Augustine, in which the baptism of infants and children played an essential role in their salvation from the ancestral guilt of original sin.
The Petrobrusians are quoted as saying, 'It is unnecessary to build temples, since the church of God does not consist in a multitude of stones joined together, but in the unity of the believers assembled.
[9] The third error enumerated by Peter the Venerable was that the Petrobrusians "command the sacred crosses to be broken in pieces and burned, because that form or instrument by which Christ was so dreadfully tortured, so cruelly slain, is not worthy of any adoration, or veneration or supplication, but for the avenging of his torments and death it should be treated with unseemly dishonor, cut in pieces with swords, burnt in fire.
They say, 'Oh, people, do not believe the bishops, priests, or clergy who seduce you; who, as in many things, so in the office of the altar, deceive you when they falsely profess to make the body of Christ and give it to you for the salvation of your souls.
'"[6] The term, transubstantiation, used to describe the transformation of the consecrated bread and wine into the body and blood of Christ, was first used by Hildebert de Lavardin in about 1079.
Therefore those things are pointless that are done by the living for the dead, because they are mortal and have passed by death beyond the way for all flesh, into the state of the future world, and took with them all their merit, to which nothing can be added.
In that year, the Benedictine monk and English chronicler Matthew Paris related that a young girl who claimed to be miraculously inspired by the Virgin Mary was reputed to have converted a great number of the disciples of Henry of Lausanne.