The predominant theme of Tertullian’s Apology is that Christianity is not only a true religion but also the truth, unlike all the different idolatrous religions and manmade philosophies known throughout the Roman Empire. Christianity is not just one more religious option; it replaces all other religions and philosophies. Despite superficial similarities between those religions and aspects of Christianity, those other religions are inherently false because they originate from human minds, not from God. It was the insistence on the divine origination of Christianity that caused Tertullian to hurl his famous question at the accusers of Christianity: What has Athens to do with Jerusalem? What does all the knowledge of this world matter when one should live life for the sake of eternal salvation?
Tertullian was not a systematic thinker or theologian. His writings were controversial, both within the Christian community and in wider non-Christian circles in the empire. The Apology is addressed to non-Christian Roman governors, so there is no doctrinal development in it. Nonetheless, the Apology was quickly translated into Greek for the benefit of Christians in the Eastern Roman Empire. They modeled their defense of Christianity after Tertullian’s Apology.
In later writings, Tertullian returned to ideas mentioned in passing in the Apology. His “Letter to Scapula” discusses in detail the fact that religious belief cannot be coerced and that only bad officials seek to compel assent. His writings against heretics, “Against the Heathens” and “Against the Valentinians,” reinforce his contention that other religions are merely human constructs. The respect due to believers who die as martyrs is detailed in “Scorpiace,” and the reasons Christians are forbidden to attend public festivities forms the basis for “Spectacles.”
There is little evidence that Tertullian’s logically rigorous defense of Christianity made any difference to Roman authorities. Persecution of Christians continued for another hundred years until Emperor Constantine issued the Edict of Toleration in 312 c.e. Regardless of the effectiveness of his explanation and defense of Christianity, Tertullian is considered the father of Latin theology because he provided the theological vocabulary for later Latin Christian writers.