In calling them the Apostles of the Churches, he might be understood in two senses — either as meaning that they had been set apart by God as Apostles to the Churches, or that they had been appointed by the Churches to undertake that office. The second of these is the more suitable. They are called also the glory of Christ, for this reason, that as he alone is the glory of believers, so he ought also to be glorified by them in return. Hence, all that excel in piety and holiness are the glory of Christ, because they have nothing but by Christ’s gift.