He has inhibited discussion by designating admonition as the method of dealing with a heretic- and the first method, too, because he is not a Christian. This is so that he would not seem to require correction again and again and before two or three witnesses as though he were a Christian. He ought to be corrected for the very reason that he is not to be disputed with. In addition, this is said because a controversy over the Scriptures can, clearly, produce no other effect than help to upset either the stomach or the brain.
TertullianAll the Scriptures give clear proof of the Trinity, and it is from these that our principle is deduced...the distinction of the Trinity is quite clearly displayed.
TertullianWhen we are going to enter the water ... in the presence of the congregation and under the hand of the president, we solemnly profess that we disown the devil, his pomp, and his angels. After this we are immersed three times, making a somewhat larger pledge than the Lord appointed in the Gospel. Then we are taken up [a reference to the Roman tradition of recognizing a newborn baby as a member of the family]. We first taste a mixture of milk and honey and from that day we refrain from the daily bath for a whole week.
Tertullian