The legalization of Christianity by Roman Emperor Constantine I (272–337) in 313 with his Edict of Milan marked the beginning of a period lasting up to the Reformation and Enlightenment that some call “Christendom.” Religious toleration in the empire created conditions for the freedom and growth of Christianity to be sure, but when in 391 Emperor Theodosius I made Christianity the Roman Empire’s official religion and in the following year outlawed any form of pagan worship, the church began to be the controlling influence in the entirety of the empire.
This shifted what had once been a severely persecuted church to the center of western society, eventually leading to what many believed to be a “Christian civilization.” From an evangelical perspective, the dominance of Christian thought during this period had some positive results culturally and even theologically, including for corporate worship.
First, persecution against Christians ceased, allowing for freedom of worship, which also provided for the expansion of the liturgy. Additionally, pagan influence over the broader culture was progressively limited significantly, and the church was granted more moral impact in the society at large. Constantine declared Sunday to be an official day of rest, forbidding merchants to trade and closing administrative offices. Since financial support for the church began to be raised through mandatory taxes, this allowed church leadership to shape worship based on what they believed to be best rather than on popular opinion. In fact, the church began to dictate popular opinion; Christianity permeated all of life, including the cultural and artistic endeavors of broader society. Individuals during this period continued to hold a worldview in which they considered reality to be outside themselves—they were part of something larger and transcendent, and the world in which they lived was marked by sin and frailty.
Yet the increasing Christian influence provided people a revelation from the Creator of that reality that gave them some hope and direction for life. Thus, they interpreted all of life in its relationship to Scripture and the Church. In other words, to a large extent, Christianity began to be the dominant influence over the worldview and theology of western civilization and thus created the cultural conditions for developing reverent, ceremonial worship and cultivated high art. As Quentin Faulkner notes, “The church’s liturgy, therefore, was splendid, ceremonial, and ritualistic in part because it was considered to be the divinely revealed earthly counterpart of the worship of God in heaven.”
However, these same freedoms and benefits also created conditions for problems to develop. Because Emperor Constantine confessed himself to be a Christian and Theodosius later made Christianity the official religion of the empire, significant numbers of people now began to attend church and identify with Christianity, many of whom had never truly converted. In one sense this was positive—scores of people were now exposed to the Word of God; but it also led to many people believing that citizenship in the empire equated with being a Christian, removing the necessity for sincere personal faith in Christ. It also caused difficulties for church leaders. For one thing, they had to find buildings large enough to accommodate all of the people, and thus they procured basilicas originally used as public Roman buildings. What were once simple worship services became elaborate ceremonies in these much larger buildings with bigger congregations. This contributed to a measure of appropriate reverence for the transcendence of God, but often neglecting the immanent, personal nature of God communicated in Scripture. Whereas smaller churches exercised a certain measure of flexibility in liturgy, although certain elements between churches would have been the same, now liturgies began to be prescribed. A significant reason for this was the fact that, in order to accommodate the larger congregations, ministers were ordained to serve sometimes without necessary training; thus theologically educated church leaders prescribed liturgies for the untrained ministers in order to keep them orthodox. Religious freedom, certainly desirable for Christians, also left room for heresy; therefore, eventually church leaders attempted a uniformity of worship practice and creed in order to stem the tide of heresy. Over time, this emerged as a standardized hierarchy of bishops, priests, and deacons and a strict clergy/laity distinction. Further, in an attempt to mimic the worship of heaven, an emphasis on absolute perfection in the liturgy gradually minimized openness by the leadership for “lay” participation. The clergy eventually became mediators between God and the laity, offering acts of worship on behalf of the people.