I don’t know if you’ve thought about why most of us don’t keep the Sabbath, but keeping the Sabbath is, after all, one of the ten commandments.
Some Christians would say that Sunday is the Sabbath. Catholics and Mormons would agree on this, and a lot of Protestants would as well. It may not matter much which day of the week the Sabbath falls on, but if we’re supposed to keep the Sabbath, why would we keep it on the first day of the week rather than the 7th? God did give a reason that he chose the 7th day as a day of rest.
The reason things are this way is because you are keeping a very ancient tradition. For those who do not keep a Sabbath at all, I would say that tradition is apostolic … sort of.
Why We Don’t Keep the Sabbath
The following is not a discussion of why you shouldn’t keep the Sabbath. It’s a discussion of why you don’t. It doesn’t matter whether you agree with what follows; what follows is still why we Christians do what we do (or don’t do what we don’t do).
All we know for certain from the apostles is that Paul said that the Sabbath is a mere shadow of things to come (Col. 2:16) and that Christians don’t have to hold one day above another (Rom. 14:5-6).
But after the apostles? Then we know a lot. The early Christians believed that Jesus did not only "fulfill" the Law of Moses, he "filled" it as well. He brought it to its full state, so that now we not only avoid adultery, we avoid lusting (right?). We not only keep our oaths, we honor every word that comes out of our mouths. (Matt. 5:17ff and fuller explanation here)
Also, we don’t just sanctify the 7th day, we sanctify every day. Because our salvation is not physical, as it was with the ancient Israelites, our rest is not physical, either. We have entered a new Sabbath, the perpetual rest we have in Christ.
That’s what early Christians taught across the board in the 2nd and 3rd centuries, and the practice of not bothering to rest on Saturday has come down to us, but the reason for that practice has not.
Because the reason was forgotten, along with a lot of other things that were forgotten, Christians began asking, rightly, "Why aren’t we keeping the 4th commandment?"
(Except medieval Roman Catholics, who had to ask, "Why aren’t we keeping the 3rd commandment?" The RCC didn’t like the command about not making graven images, so they took it out, which they could get away with because they wouldn’t let their captives read the Bible. But that’s a different tradition.)
The response to this question could not be "Let’s go back to resting on the 7th day" because the tradition against it was too well-established. Thus began the practice of resting on the 1st day, the "Christian Sabbath."
Early Christians honored the first day, too, but not as a Sabbath. It was a day of rejoicing. On Sunday they did not kneel or fast. They also held their weekly meeting on that day, though it was early in the morning so that everyone could get to their fields or business after the meeting. It was not a day of rest. Even for the Romans, the great day of Saturn was the chief day of the week, not the day of the Sun. Everyone worked on Sunday, and if there was a day of rest, it was the 7th day for the Jews, and the same day, the day of Saturn, for the Romans.
But because the 1st day was a day of joy in honor of the resurrection, it was the primary candidate for restoring the physical rest that properly belongs to the Old Covenant.
Should We Keep the Sabbath?
Ah, that’s the question. But it’s a question for tomorrow. It’s not the answer that I want to talk about, it’s the answering.
So "Reasoning, Part One" was devoted to actually thinking about why we don’t keep a 7th day Sabbath. Part Two will be devoted to whether we should just accept tradition as it’s handed to us, and Part Three will discuss the terrible temptations we face when we discuss such issues.