EDITOR'S NOTE: The following is an excerpt from The End of Secularism by Hunter Baker. (Crossway).  

Chapter One: The Early Church and the Empire

As defined in the introduction, secularism means that religious considerations are excluded from civil affairs. We live in a time when public secularism is something of a taken-for-granted reality in the United States. Although the U.S. is one of the most religious of the developed nations, there is still an expectation among those who define public reality in the media, academy, and government that appeals to God should be saved for one's private life. When someone breaks the pattern by publicly invoking God as the reason to either embark upon or avoid a course of action, the reaction is typically one of distaste, surprise, or feeling threatened. The reason for the adverse reaction is that secularism is widely believed to be rationally more attractive than the alternatives and a superior strategy for attaining social peace in a pluralistic setting. To swim against the tide of secular modernity indicates one may be uncivil, unbalanced, and possibly even dangerous.

The question posed by this book is whether public secularism is desirable and, more specifically, whether it lives up to its billing. In order to answer that question, it is useful to look back at how we reached the current cultural and political moment, in the West generally and in the United States specifically. Just as atheism is by definition a reaction against something, which is belief in the existence of God, so too, is secularism a reaction against something. In the West, where the concept was born, secularism is a reaction against the notion of a religious state, particularly a Christian one. Thus, if one proposes to make a critical study of secularism, then one must obtain a degree of familiarity with the story of the Christian church and the state since the time of Christ.

The Rise of Christianity and the Challenge of Power
For most of human history, religious and political authority has been unified. Typically, both governmental and religious rule have been united in a single structure or the two have occupied distinct organizations but with a mutually reinforcing relationship.1 Christians and non-Christians often attribute the eventual growth of church-state separation in the West to the enigmatic statement of Jesus who famously said, "Render to Caesar the things that are Caesar's, and to God the things that are God's."2 The statement referred to a coin bearing Caesar's image and appears pregnant with possible meanings, but a common lesson drawn from the scriptural moment, employed repeatedly for two millennia now, is that God cares about sacred things, such as a pure heart and religious observance, and delegates more prosaic matters such as regular law, order, and commerce to earthly rulers. This single interpretation of what Jesus meant—the idea of separating the sacred from the pragmatic business of community governance—is the seedling of the modern secular arrangement of public affairs. In fact, secularism is sometimes referred to as the gift of Christianity to the West.3

Although the Christian thus instructed aimed to be a good citizen of the empire into which the early church was born, obedience carried one important caveat. God must be obeyed rather than men, so where God's law differed from the law of men, Christians were forced to follow the higher law.4 The paradigmatic example of a clash between the two realms involved emperor worship. At first, Christians were able to employ the same exemption from the practice that Jews enjoyed, but ultimately the government sorted out the two camps and began to persecute stiff-necked Christians whose refusal to subordinate their unique religiosity to the civil cult of the emperor posed an apparent threat to the legal order.5