73. Let it therefore be pronounced of no effect that they baptize, who hear the words of God and do them not, when they shall begin to pass from unrighteousness to righteousness, that is, from the sand to the rock. And if this is not done, because what there was in them of Christ was not violated by their unrighteousness, then let this also be understood in the case of heretics: for neither is there the same hope in the unrighteous, so long as they are on the sand, as there is in those who are upon the rock; and yet there is in both the same baptism, although as it is said that there is one hope, so also is it said that there is one baptism.