On Baptism by Tertullian
Chapter I.--Introduction. Origin of the Treatise.
Happy is our sacrament of water, in that, by washing away the sins of our early blindness, we are set free and admitted into eternal life! A treatise on this matter will not be superfluous; instructing not only such as are just becoming formed (in the faith), but them who, content with having simply believed, without full examination of the grounds of the traditions, carry (in mind), through ignorance, an untried though probable faith. The consequence is, that a viper of the Cainite heresy, lately conversant in this quarter, has carried away a great number with her most venomous doctrine, making it her first aim to destroy baptism. Which is quite in accordance with nature; for vipers and asps and basilisks themselves generally do affect arid and waterless places. But we, little fishes, after the example of our IChThUS Jesus Christ, are born in water, nor have we safety in any other way than by permanently abiding in water; so that most monstrous creature, who had no right to teach even sound doctrine, knew full well how to kill the little fishes, by taking them away from the water!