Johannes Quasten, Patrology, vol. II: The Ante-Nicene Literature After Irenaeus (Westminster: Christian Classics, 1990) 246-247.
Tertullian was a Christian thinker who lived in the second-third centuries C.E. Here are some quotes about him, along with my comments:
...the African writers [such as Tertullian and Cyprian] testify better than all other Latin authors of the West to the great difference between Greek and Latin Christendom...The comparison between the great theologians of both sides will show this immediately. Whereas Clement of Alexandria and Origen [of Greek Christianity] are anxious to put in relief the metaphysical content of the gospel and to prove the faith the only true philosophy and far above the Hellenistic systems, Tertullian and Cyprian [of Latin Christianity] set great store by the Christian way of life against the background of pagan vice. The Alexandrians stress the objective value of redemption, based on the incarnation of the Logos, which filled mankind with divine power; the Africans focus their attention on the subjective side of salvation, i.e., what remains to be done by the individual, i.e., the Christian's fight against sin and practice of virtue (246).
[Tertullian] does not tell us the reasons for his conversion [to Christianity]. Evidently it was not a careful comparison of the various philosophical systems which led him to the faith, as was the case with St. Justin. It seems that the heroism of the Christians in times of persecution influenced him more than anything else...(247).
Quasten makes it sound as if the Greek-speaking Christians (i.e., Clement, Origen) were more interested in reconciling Christianity with Greek philosophy and demonstrating Christianity's superiority to Greek philosophical systems. The Latin-speaking Christians, by contrast, focused more on ethics. Tertullian was drawn to Christianity, for example, because he was impressed by the strength of character that Christian martyrs demonstrated.
I wonder how the Greek-speaking Christians sought to demonstrate the superiority of Christianity to other belief systems. How can a person prove that one belief system is right while others are wrong, especially when Christianity is so based on faith, belief in the unseen? Quasten's discussion of Origen's Contra Celsum (54-55) gives us insight into some of Origen's apologetic approach: We know Christianity is true on account of fulfilled prophecy, miracles, and its conversion of many people, some of whom were once hostile to Christianity. Origen also mentions martyrdom.
In Dialogue with Trypho 2-8, Justin Martyr discusses the various philosophical systems that he encountered before he became a Christian. He was disappointed with many of the schools because he didn't feel that they led him to God. The Christian who brought him to Christ discussed with him such issues as the immortality of the soul, creation, fulfilled prophecy, and the happy life, which is the aim of philosophy. He convinced Justin that the world was created by a supreme being. I'm not sure if Justin grounds Christianity in a solid foundation, but maybe he thought that he was.
Is there a solid epistemological foundation for Christianity? I don't know. Maybe Origen is correct that we can see unusual occurrences that point us to the activity of the Spirit. Perhaps there is a subjective feeling of intimacy with the divine that Christianity brings certain people, something that they don't find in other belief systems. Fulfilled prophecy doesn't convince me that much, for Jews and biblical scholars have alternative ways to interpret the prophecies that supposedly point to Jesus. Does the lifestyle of Christians impress me? Not all Christians make a good impression, but there are some.
I knew a person at Harvard who was once an atheist and a Marxist, and he became a Christian when he went to a prayer group on a regular basis. As he saw God's work in the lives of Christians, he became convinced that the God of Jesus Christ was real. He became a Christian on the basis of experience.
In a philosophy class at DePauw, an atheist professor asked her students how people can know that there is a God. One of them (not me) replied, "By going to church." The professor didn't think much of that student's answer, but is there something to it? Maybe we can grow in faith as we see answers to prayer and unusual events. This happens when we participate in Christian community.
That's something that I'm missing right now, since I don't really participate in evangelical churches or small groups. But, on some level, I do see it in Alcoholics Anonymous, as I hear about changed lives and answers to prayer: God's doing for people what they cannot do for themselves. AA is not an explicitly Christian movement, which can lead one to the question of whether God blesses those who don't believe in Christ. I don't know. Maybe he rewards all sorts of people who seek him in faith. That could be one way that he draws them to Christ.