The Romans knew well the twin concepts of representation and representatives in law suits and in the relationships between father and son, and owner and slave. But for these concepts they did not use the terms repraesentare or any cognate.
To Tertullian, it seems, goes the credit of first using repraesentare and repraesentator in their modern senses of <> and <>. That his context is theological probably should not surprise since he is, above all, a theologian.
Thus he uses repraesentare to mean that the one larger and more important may represent the many and less important. This usage had a long and successful future.
More importantly perhaps, he claims that he made manifest the conjunction of two persons, that the Son would be the representative of the Father, and that the Father is in the Son and the Son is in the Father. They are one being. It is no doubt fanciful to see here a reminiscence of the Roman patria potestas but we must remember that Tertullian somehow had some legal knowledge.
Lastly, the Better God does not reject the good works of God the Creator including those by which he nourishes his people, <>, a clear reference to transubstantiation.
Repraesentatio in Classical Latin
Available at: http://digitalcommons.law.uga.edu/fac_artchop/9