The Israel of old was already called the Church of God while it was on pilgrimage through the desert. So the new Israel, as it makes its way in this present age, seeking a city that is to come, a city that will remain, is also known as the Church of Christ, for he acquired it by his own blood, filled it with his Spirit, and equipped it with appropriate means to be a visible and social unity. God has called together the assembly of those who in faith look on Jesus, the author of salvation and the principle of unity and peace, and so has established the Church to be for each and all the visible sacrament of this unity which brings with it salvation.