Christianity became the official religion of Rome in the 4th century. The prestige and status as the official religion of Rome, was given as a reward to the Christian soldiers who fought for Rome. They were the best soldiers of the empire, highly skilled and unafraid of death. Rome hoped this religion would rub off on the rest of the empire, to assure Rome's survival.
This merger changed both Christianity and Rome, with the combined State-Church becoming a hybrid of both; render onto Caesar what was Caesar's and render onto God what was God's. The New Roman Catholic Church became a paradox of opposites; turn the other cheek, and then kick butt and conquer. Faith was now supported by secular technology and science. Blessed are the poor while accumulating vast wealth. Christianity and Atheism even existed together, with godless decisions often made in high places. This altered the original Christianity for the needs of the secular empire. Rome declined in terms of the original empire but remained alive as the hybrid.
This hybrid lasted for about 1000 years, until about the 14th century and the Age of Exploration. This is when the Western nations, under the central Roman Catholic Church, began to expand and explore the world at large for trade and territory. This began a process, similar to a cell cycle where the mother cell was preparing so she could split into two daughter cells.
The result was first a division in the Catholic Church, followed by cultural divisions along the lines of pre merger Christianity and pre merger Rome. The Age of enlightenment appears. The old Roman installed monarchies began to fall. The Nazis took the Roman side of the split to the extreme. The battle between atheism and religion is a continuing part of this splitting process. One can even see the cell division process in politics; the atheist heathen Left; Roman Globalism, and the more passive Christian right.
I personally like to maintain the merger of the two daughter cells within myself, even if they are opposites. This is the symbolism of suspension on the cross hanging between two thieves. One thief can understand, while the other thief cannot. It is faith that allows this odd state of suspension to sustain.
I was brought up as a Catholic, who after being confirmed at age 13, followed a science education and dabbled in other Christian sects and world religions including Pagan rituals. This caused me to became more agnostic, while the science education slanted me toward atheism. After graduation from college, I became a development person and as private development project, I performed unconscious mind experiments on myself to explore the collective unconscious firmware. It turned out that success in this research required both reason; sword, and faith; shield, since reason alone was not enough to deal with some of the scary 3-D and 4-D firmware affects that had no precedent in the literature. The sword and shield taught me how to stay in the middle, which now allows the best of both worlds. The suspension gives creative energy.