Christianity had a profound effect on all of western culture. Much of it had to do with the concept of the individual and individual freedom. Ironically much of these changes had nothing to do with the core beliefs of the religion, but with the peripatetic nature of Christ's teaching. Christ admonished his followers to leave everything and follow him in a time when even free men were slaves to their occupations. Also, he challenged authority. He argued his case with Rabbi’s and governors as one man against the system.
If you look at non-Christian societies you will see less emphasis on the individual, and more on the society as a whole. The Chinese have a sort of sector rule; get the dissidents out of the sector for harmony's sake. This type of rule pre-dates communism.
The Greeks, of course, wrote much in the area of philosophy, but non more than Plato. His dialogues influenced a multitude of societies. His student, perhaps a greater philosopher than himself was Aristotle. Aristotle took Plato's philosophy, critiqued much of it and then expanded his own ideas through it. His was much more studious than Plato it would seem, and interested in far more subjects, including: biology, astronomy, physics, mathematics, psychology, and of course the subsequent branches of philosophy. Plato's philosophy would be expanded by a man named Plotinus later on through history. Plotinus is known as the father of neo-Platonism. Plotinus influenced one of the greatest, most influential Christian thinkers in history: St. Augustine. St. Augustine took Plato's philosophy and made it compatible with Christian doctrine. Later, St. Thomas Aquinas, in the middle ages, would recognize some problems this would have towards the Christian doctrine and then reconcile Aristotelians with Christian doctrine. Aristotelians and Platonism had had the most profound affects on Christianity in history. Some of the early church fathers, such as Origin, became too involved with Platonic notions of...