Common Service Times for Christians
For thousands of years before Christianity took its foothold through the world, Jewish adherents designated their day of rest, the Sabbath, on the last day of the month. This coincided with the creation of the world as told in the Book of Genesis as the day God rested from His work after the Earth was made. This article breaks reasons down as to why Christianity, which stems directly from Judaism and its culture, started recognizing Sunday, the first day, as its day of rest.
Christ's life as the fulfillment of Mosaic Law
Before Jesus Christ, the Law of Moses was in full effect; the state recognized and enforced the Sabbath day rest. The rules went as far as stoning people or banishing them from communities for refusing to stop all work. When Jesus Christ preached, he proclaimed that he was the fulfillment of the Law of Moses. Whereas the Law of Moses was given to the Children of Israel as a tangible, acts-based law system, Christ brought forth laws of the heart and of the spirit. When Pharisees wagged their tongues that the Apostles were picking grapes off of the fields to eat on the Sabbath, calling it a sin and work, Jesus taught that, "Sabbath was made for man and not man for the Sabbath." This shows that obedience to the spirit of the law is as important as the letter. Why should someone starve simply because it was a Saturday? Much more, this shows that the Sabbath and its associated resting is of the heart, and was given so that other men could and should not compel others to work on that day. In that way it was a beneficial day to gather as families to worship and learn.
Jesus' resurrection as an impetus for change
Christ suffered and died on the cross on a Friday. He was given a humble burial in a borrowed tomb after living a life without sin. As he suffered and bled in the Garden of Gethsemane, he took the sins of the world upon himself and then died to seal the sacrifice. He rose from the dead three days later a perfected being of flesh and bone. The Resurrection, Christ's triumph over death, is the promise to everyone that they too can overcome death and, if worthy, can live with Him again. While it is hard to say that anything is more important than Creation itself, saving all humankind from an eternal agonizing death is something to recognize as incredibly special. As Christianity spread, it took this new day, the first of the week, as a day to celebrate, gather and learn, as was always done on Saturdays before His resurrection. This set them apart from Judaism and gave them an identity and since, as Jesus said, the Sabbath was made for man, the actual day it is observed is probably not as important as the observation itself.
Seventh-Day observers
A sect of Christianity that falls neither under Catholicism nor Protestantism, the Seventh-Day Adventists, follow the ancient day of observance as Saturday. Many strict Adventists go as far as refusing to use incandescent lights, as they make fire, which was strictly forbidden in the Mosaic Law, or work after sundown on Friday night until sundown Saturday night.
Although there are some sects of Christianity that still adhere to the anti-Christ ways of Sabbath worship on Saturday, almost all others see Sunday as a natural Sabbath. Due to the perfect life, sacrifice and resurrection of Jesus Christ on Sunday, most Christians see fit to worship on that day.