Christian learning was a complex issue, because, strictly speaking, spiritual salvation was thought to be available to anyone simply by accepting the basic tenets of Christian doctrine. In other words, the whole intellectual world of Greek and Roman philosophy, literature, science, and so on did not necessarily relate to the church's primary task of saving souls. Many church leaders were learned men and women, however, and insisted that there was indeed a place for learning within Christianity. The issue was never settled - one powerful church leader, Tertullian, once wrote “what does Athens have to do with Rome?”, meaning, why should anyone study the Greek intellectual legacy when it was produced by pre-Christian pagans?
Once Christianity was institutionalized, church leaders generally came around to the importance of classical learning because it proved useful for administration. A vast Greco-Roman literature existed describing governance, science, engineering, etc., all of which was necessary in the newly-Christian Empire. A kind of uneasy balance was struck between studying classical learning, especially things like rhetoric, while warning against the spiritual danger of being seduced by its non-Christian messages.
The most important thinker who addressed the intersection of Christian and classical learning was St. Augustine of Hippo (a Roman city in North Africa), whose life spanned the late fourth and early fifth centuries. Augustine lived through the worst period of Roman decline, completing his work while his own city was besieged by Germanic barbarians called the Vandals. To Roman Christians, this posed a huge challenge - if all-powerful God had embraced them, why was their Empire falling apart? Augustine's answer was that life on earth is not ultimately significant. In his work The City of God, Augustine distinguished between the perfect world of heaven, attainable through Christian faith, versus the flawed and imperfect world of the living. This concept explained the decline of the Empire as being irrelevant to the greater mission of salvation. Thus, according to Augustine, all of learning was just a facet of material life; useful in its way but totally insignificant compared to the necessity of laying one's soul bare to God and waiting for the second coming of Christ.
The irony of these struggles over Christian doctrine versus ancient learning was that the issue was decided by the collapse of Rome. When Rome fell to Germanic invaders in the mid-fifth century, so began the decline of organized learning - there simply was no funding from Roman elites for what had been a robust private school system. In the absence of instruction, literature and philosophy and engineering all but vanished, preserved only in monasteries and in the eastern Empire. Once the western Empire collapsed, the church was the only institution that still supported scholarship (including basic literacy), but over time the levels of literacy and education in Europe unquestionably declined - this decline inspired the contempt of later Renaissance thinkers who wrote off the period between the fall of Rome and the beginning of the Renaissance in about 1300 CE as the “Dark Ages.”