The Lord's Prayer "is truly the summary of the whole gospel." "Since the Lord...after handling over the practice of prayer, said elsewhere, 'Ask and you will receive,' and since everyone has petitions which are peculiar to his circumstances, the regular and appropriate prayer (the Lord's Prayer) is said first, as the foundation of further desires.
Tertullian[T]he Father, the Son, and the Holy Ghost [are] three ... not in condition, but in degree; not in substance, but in form; not in power, but in aspect; yet of one substance, and of one condition, and of one power, inasmuch as He is one God, from whom these degrees and forms and aspects are reckoned, under the name of the Father, and of the Son, and of the Holy Ghost.
TertullianThe Word, then, the Christ, is the cause both of our ancient beginning, for lie was in God, and of our well-being. And now this same Word has appeared as man. He alone is both God and man, and the source of all our good things
TertullianHe 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.
Tertullian