Augustine of Hippo is considered the most influential theologian in the history of the Church in the West. Augustine developed a sexual ethic that became decisive for later teachings on issues of marriage, reproduction and sexuality. Some of the most significant passages are reproduced here.

Among the voices that come across the centuries from early Christianity, few speak with sharper accents, or in more highly colored tones, than that of Tertullian. First in the Latin-speaking West to leave a major corpus of writings, Tertullian is also the first in the West to address in both treatise and tract the issues confronted by Christians in their encounter with the surrounding pagan world. Tertullian belonged to an era when Roman imperial power was at its height and paganism could proudly claim the blessings of the widespread Roman civilization. Though it was an officially tolerant...

Outside the New Testament, our earliest complete witness to Christian apologetic against the Jews remains the Dialogue with Trypho, written by Justin Martyr (circa 165), a convert to Christianity from traditional Greek religion. The Dialogue purports to be a two-day dialogue that took place in Asia Minor between Justin and Trypho, a Hellenized Jew. Justin argues extensively on the basis of lengthy Old Testament quotations that Christ is the Messiah and God incarnate, and that the Christian community is the new Israel. In the beginning of the work Justin recounts how he converted to...