Why do most Christians call Sunday the Lord's day? I was reading through a Bible and was surprised to find in Matthew 12:8 that Jesus Himself says..."For the Son of Man is Lord of the Sabbath." If Jesus says He is Lord of the Sabbath wouldn't that make Sabbath -- which was Saturday as my neighbors, the Jews, keep it -- the Lord's Day? I'm only 19 and I and several friends have been searching, mostly reading C.S. Lewis because he seems to be widely accepted, but I was curious about that text.
The phrase "Lord's Day" actually only occurs in Revelation 1:10 and I do not think that it is possible from the context to determine which day of the week is being talked about. The grammatically equivalent phrase "Day of the Lord" occurs 23 times. The Day of the Lord, though, has different meanings depending on the context. Some examples:
- Isaiah 13:6 "Wail, for the day of the LORD is near; it will come like destruction from the Almighty." In this use, the Day of the Lord is referring to the time of the Lord's execution of judgment on the Babylonians. The Babylonians fell in 539 BC.
- Ezekiel 13:5 "You have not gone up to the breaks in the wall to repair it for the house of Israel so that it will stand firm in the battle on the day of the LORD." Here the same phrase is used, but it refers to a different time. This time it is referring to the fall of Jerusalem by the Babylonians which occurred around 586 BC.
- Joel 2:28-31 "And afterward, I will pour out my Spirit on all people. Your sons and daughters will prophesy, your old men will dream dreams, your young men will see visions. Even on my servants, both men and women, I will pour out my Spirit in those days. I will show wonders in the heavens and on the earth, blood and fire and billows of smoke. The sun will be turned to darkness and the moon to blood before the coming of the great and dreadful day of the LORD." This use by Joel, on the surface would seem to parallel Ezekiel, however, Peter quotes these verses in Acts 2:17-21 and says that they find their fulfillment on that day, the day of Pentecost when the first sermon is preached. Therefore this "day of the Lord" refers to the time around the death of Jesus on the cross and the beginning of his church or roughly 35 AD.
- I Thessalonians 5:1-2 "Now, brothers, about times and dates we do not need to write to you, for you know very well that the day of the Lord will come like a thief in the night." This time Paul is using the phrase to denote the time of the end of the world.
On the other side of the issue is the references to the proper day of worship. Jesus was raised from the dead on the first day which is recorded in all four gospels. Then Acts 20:7, "On the first day of the week we came together to break bread. Paul spoke to the people and, because he intended to leave the next day, kept on talking until midnight." We gather from this, then, that the day to assemble and partake of the communion is the first day of the week, Sunday.
As you noted, Jesus said that he was Lord of the Sabbath in Matthew 12:8 and other passages dealing with the same event. The issue that we need to determine is whether Jesus meant he was Lord of Saturday, Lord of the Sabbath regulation, or Lord of the origination of the Sabbath. The complexity comes from Exodus 20:11, "For in six days the LORD made the heavens and the earth, the sea, and all that is in them, but he rested on the seventh day. Therefore the LORD blessed the Sabbath day and made it holy." In the Mosaical Law, the reason that Saturday is a holy day is that God rested on that day when he made the world. The easiest thing to do is look at the three possibilities and see if they mesh with other scriptures.
Here was the scenario, (Matthew 12:1-2 "At that time Jesus went through the grainfields on the Sabbath. His disciples were hungry and began to pick some heads of grain and eat them. When the Pharisees saw this, they said to him, 'Look! Your disciples are doing what is unlawful on the Sabbath.'" He explains the reason for it and then ends his argument by saying in verse 8, "For the Son of Man is Lord of the Sabbath."
- Jesus is Lord of Saturday. While technically true, it would carry very little meaning in the context. The Sabbath without its religious implications has no real significance. What could Jesus gain by claiming to be in charge of Saturday?
- Jesus is in charge of the Mosaical regulations about the Sabbath. This would be hard to do. In Matthew 5:17 Jesus had said that he did not come to destroy the law. Yet, if he meant that he was setting aside the law (for he lived under the law), then that would mean that he was authorizing the destruction of the law.
- Jesus is in charge of the origination of the Sabbath. Now this one is hard to grasp, but that would not be the only time. In Matthew 19 Jesus appealed to the beginning and he may be referring to the beginning here also. Note in the above quote of Exodus 20:11, that the purpose for the Sabbath was to honor the formation of the world and the day that God rested. Speaking of Jesus in Colossians 1:16, Paul says, "For by him all things were created: things in heaven and on earth, visible and invisible, whether thrones or powers or rulers or authorities; all things were created by him and for him." Since Jesus was at the creation and was the creator, then when God rested, that meant that Jesus also rested on that day. This then makes the most sense in the context. Jesus was saying that the reason his disciples could eat was that the whole concept of the Sabbath was to honor Jesus and his work. Ergo, it was his day and he could have his disciples deal with it in any way he wanted. More importantly, it would seem by his conduct and the way he was dealing with the topic is that he was ultimately authorizing his disciples to be released from ties to the Sabbath as a day of no work.
That, in a nutshell, is all that we can glean from the Bible on the topic. There is a lot of debate on how the term "Lord's Day" came into common usage to refer to Sunday. For that, you would have to consult scholars who like to delve into that type of thing. It's usage, though, can be traced to works thought to be as old as 110 AD. That puts it very close to the book of Revelation which has estimates on when it was written of between 70 - 110 AD.
I have personally never read any of C.S. Lewis's works. I would assume from what I have heard that he was a knowledgeable man. While we can learn from one another it is important to realize that the true author of salvation is Jesus. We need to always look to his word for answers to our need for salvation. Keep reading the Bible, in it is the path to salvation.