Tertullian wrote over a dozen surviving works and even more that we know about from antiquity. I will only deal with those selected by Drobner as the most influential: 1) Apologeticum. This apology is the masterpiece of second-century apologies and both attacks pagan religion and then defends Christianity as an ancient religion producing morally superior citizens. He answered the standard objections to Christianity prevalent in the Roman Empire. 2) De anima. Here, T. rejected the Platonic (and, to a lesser extent, Stoic) doctrine of the soul, which he claimed was the origin of all heresies. 3) De praescriptione haereticorum. T. employs the Roman judicial practice of the praescriptio, which strengthens one's one evidence while minimizing the evidence of the opponent, to argue against the heretics. They are guilty of falsifying Scripture and are inconsistent with church tradition. As with De anima, philosophy is one of the main sources of heresy. 4) Adversus Marcionem. T. most extensive treatise, where he refutes the key heretic Marcion, using arguments from Irenaeus, Justin, and Theophilus of Antioch. T. argues Marcion's teaching that the God of the OT is not identical with the Father of Jesus Christ who is the bodily appearance of the Father. Also, T. opposes M.'s truncated Bible by showing even his authorized passages refute his own views. 5) Adversus Praxean: T. refutes a monarchian view of God by appealing to (a) analogy, namely that God's rule is like the reign of the Roman Emperor and his sons as co-regents without division in the kingdom and (b) Scripture.

His writings can be classified as apologetic, anti-heretical (praes;bapt; adv. Hermogenem;asv. Praxean; adv. Marc.), parenetical (on persecution, dress, virtues [patientia, oration, ieiunio, paenit, pudicitia]

It is difficult or impossible to assign a coherent theology to T. because he wrote for specific occasions and was not one who systematized. He displays masterful classical rhetorical form and style in his writings. He often organizes treatises along the same lines as classical rhetorical pieces. His biblical exegesis conforms to the rules of the rhetorical schools. While he used classical learning, he also relegated this learning to a distant second-place to Christian doctrine. The standard of truth for T. is the regula fidei, or the content of the Apostolic Creed. His later works show that T. believed in the ongoing revelation of God through the Spirit in prophecy.

Though his statement that Christ was two natures in one person anticipates the Chalcedonian definition, it is not clear that this writing actually influenced the Council's declaration. His Apologeticum had wide influence and distribution in both East and West. Despite this famous disclaimer, Tertullian knew how to use Athenian arguments to defend Jerusalem's truth.