But now inquiry is being made concerning these issues. First, can any believer enlist in the military? Second, can any soldier, even those of the rank and file or lesser grades who neither engage in pagan sacrifices nor capital punishment, be admitted into the church? No on both counts.
TertullianEvery soul, then, by reason of its birth, has its nature in Adam until it is born again in Christ; moreover, it is unclean all the while that it remains without this regeneration; and because unclean, it is actively sinful, and suffuses even the flesh (by reason of their conjunction) with its own shame.
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.
Tertullian