2. But again, our Saviour prays that we may be one in affection and in action; yet what possible way is there of many men acting _together_, except that of forming themselves into a visible body or society, regulated by certain laws and officers? and how can they act on a large scale, and consistently, unless it be a permanent body? 3. But, again, I might rest the necessity of Christian unity upon one single institution of our Lord's, the Sacrament of Baptism. Baptism is a visible rite confessedly, and St. Paul tells us that, by it, individuals are incorporated into an already existing body. He is speaking of the visible body of Christians, when he says, "By one Spirit are we all baptized _into one body_[6]." But if every one who wishes to become a Christian must come to an existing visible body for the gift, as these words imply, it is plain that no number of men can ever, consistently with Christ's intention, set up a Church for themselves. All must receive their Baptism from Christians already baptized, and they in their turn must have received the Sacrament from former Christians, themselves already incorporated in a body then previously existing. And thus we trace back a visible body or society even to the very time of the Apostles themselves; and it becomes plain that there can be no Christian in the whole world who has not received his title to the Christian privileges from the original apostolical society. So that the very Sacrament of Baptism, as prescribed by our Lord and His Apostles, implies the existence of one visible association of Christians, and only one; and that permanent, carried on by the succession of Christians from the time of the Apostles to the very end of the world.