 At the very beginning of his reign , he deemed it proper to promulgate by law the Church 's belief in the Trinity and the Incarnation ; and to threaten all heretics with the appropriate penalties ; whereas he subsequently declared that he intended to deprive all <unk> of orthodoxy of the opportunity for such offense by due process of law . He made the <unk> @-@ Constantinopolitan creed the sole symbol of the Church , and accorded legal force to the canons of the four ecumenical councils . The bishops in attendance at the Second Council of Constantinople in 553 recognized that nothing could be done in the Church contrary to the emperor 's will and command ; while , on his side , the emperor , in the case of the Patriarch Anthimus , reinforced the ban of the Church with temporal proscription . Justinian protected the purity of the church by suppressing heretics . He neglected no opportunity for securing the rights of the Church and clergy , for protecting and extending monasticism . He granted the monks the right to inherit property from private citizens and the right to receive <unk> or annual gifts from the Imperial treasury or from the taxes of certain provinces and he prohibited lay confiscation of monastic estates . 
