The current paper is focused on the subject of unity (Hebr. ehad) at the chosen people, which traces its root in God Only (ehad YHWH) and which is established by the event on Sinai and by the reception of the Law (Ieșirea 20). The prophets of the Old Testament would insist on the necessity of fulfilling the Torah, as a unique foundation for the maintenance of unity as a people and for monotheistic faith. God’s unity manifests itself through the unity of His people, which is why Israel undertook to abide by the Law given by God through Moses, in order to perfect themselves in this exercise of unity and coherence in faith. At the fathers of the Holy Mountain we notice the same biblical preoccupation to maintain the unity of faith, through the cultic and dogmatic fulfilment of the decisions of Œcumenical Synods. The unity of faith or pan-orthodoxy is the genuine expression of the practice of Christian virtues.