"after baptism the crossing of the desert, by a life . . . lived in hope"

"There remains, you see, after baptism the crossing of the desert, by a life that is lived in hope, until we come to the promised land, to the land of the living where God is our portion, to the eternal Jerusalem; until we get there, the whole of this life is the desert for us, the whole of it a trial and a temptation. But in the one who has overcome the world the people of God has overcome all things. Just as in baptism, after all, our past sins, like enemies pursuing us from the rear, are obliterated, in the same way after baptism, in the journey of this life, when we eat the spiritual food and drink the spiritual drink, we overcome everything that bars our way."

"restat enim post baptismum transitus per eremum, per uitam quae agitur in spe, donec ueniamus ad terram promissionis, terram uiuentium ubi nobis est portio dominus, in aeternam Ierusalem; quo donec ueniamus, tota ista uita eremus nobis est, et tota tentatio. sed in eo qui uicit saeculum, uincit omnia populus dei. nam sicut in baptismo, tanquam hostes a tergo insequentes, praeterita peccata delentur: sic post baptismum, in itinere uitae huius, cum escam spiritualem manducamus, et potum spiritualem bibimus, omnia nobis aduersantia superamus." 

     St. Augustine,  Sermon 363.3 (possibly Easter Vigil, 412/416), trans. Hill, WSA III/10, 273. Latin from PL 39, 1637, ll 29-39.