Emperor Constantine played a huge role in shaping the way Christianity is today. Did you know that the Biblical Christians in the New Testament worshiped on Saturday the seventh-day of the week? See Acts 13:42-44 for one example. In the year 321 AD Constantine passed a Sunday Law which mandated Sunday as a day of rest. Eventually Christians, in order to be popular, began worshiping on the first day of the week, like the Romans did. Check out sabbathtruth.com for more information.