Chap. ii.—2. All the more, then, because we are fighting for the honour and unity of the Church, let us beware of giving to heretics the credit of whatever we acknowledge among them as belonging to the Church; but let us teach them by argument, that what they possess that is derived from unity is of no efficacy to their salvation, unless they shall return to that same unity. For "the water of the Church is full of faith, and salvation, and holiness" to those who use it rightly. No one, however, can use it well outside the Church. But to those who use it perversely, whether within or without the Church, it is employed to work punishment, and does not conduce to their reward. And so baptism "cannot be corrupted and polluted," though it be handled by the corrupt or by adulterers, just as also "the Church herself is uncorrupt, and pure, and chaste." And so no share in it belongs to the avaricious, or thieves, or usurers,—many of whom, by the testimony of Cyprian himself in many places of his letters, exist not only without, but actually within the Church,—and yet they both are baptized and do baptize, with no change in their hearts.