Why don't Christians keep the Sabbath?

In the apostles's churches, the answer would have been, "We do." Then they would have explained that Jesus came to bring the law to fullness. While adultery was forbidden to the Jews, for the Christian even lust is forbidden. In the same way, the Jews, the earthly people of God, kept a physical Sabbath, while the Christians, the spiritual people of God, keep a spiritual Sabbath.

Physically, we cannot rest every day or we will starve. Spiritually, though, we are called into the rest that Christ brings; it is spiritual, and it can be experienced daily, even perpetually. As Colossians 2:16-17 says, "Let no one therefore judge you in eating, or in drinking, or with respect to a feast day or a new moon or a Sabbath day, which are a shadow of things to come, but the body is Christ's."

The phrase "Sabbaths, new moons, and feasts" is used 7 times in the Old Testament of the weekly, monthly, and yearly sacrifices (1 Chr. 23:31; 2 Chr. 2:4; 8:13; 31:3; Neh. 10:33; Ezek. 45:17; Hosea 2:11). There are those who argue that Colossians 2:16 is only talking about the Sabbaths that happen during feasts, but that is not correct.

"The new law requires you to keep perpetual Sabbath, and you [Jews], because you are idle for one day, suppose you are godly, not understanding why this command was given to you. If you eat unleavened bread, you say the will of God has been fulfilled. The Lord our God does not take pleasure in such observances. If there is any perjured person or thief among you, let him cease to be so. If any adulterer, let him repent. Then he has kept the sweet and true Sabbaths of God." (ch. 12)

Justin wrote that around A.D. 150, but even earlier, in either A.D. 107 or 116, a bishop appointed by the apostles (Ignatius of Antioch), wrote, "If those who have been brought up in the ancient order of things [i.e., converted Jews] have come to the possession of a new hope, no longer observing the Sabbath but living in observance of the Lord's day, on which also our life has sprung up again by him and his death … how shall we [i.e., Gentile converts] be able to live apart from him, when even the prophets themselves—also his disciples— waited for him in the Spirit as their Teacher?" (Letter to the Magnesians, ch. 9).

Around A.D. 185, one of the most respected bishops of the second century wrote, "We learn from Scripture itself that God gave circumcision ... as a sign. ... Ezekiel the prophet says the same concerning the Sabbaths: 'I gave them my Sabbaths to be a sign between me and them' ... These things, then, were given as a sign, but the signs were not lacking symbolism ... since they were given by a wise Artist; the circumcision of the flesh typified that which was of the Spirit. ... But the Sabbaths taught that we should continue day by day in God's service" (Against Heresies, Bk. IV, ch. 16, par. 1)

Another common interpretation of the Law of Moses was that the law about foods was "filled up" to mean that we are to "chew the cud" by meditating/ruminating on the Word of God, and that we are to "part the hoof" by separating from the world and living holy. God does not care about food, but about how we live (cf. Mark 7:15; 1 Cor. 6:13).

We have forgotten these things in the modern era, and so the arguments about the Sabbath put out by the Seventh Day Adventists and others do not include or answer what was taught by all Christians in the second and third centuries.

Time passed, and opposition to Jewish customs increased. The Christians were meeting on Sunday anyway because that was the day on which Jesus rose. They called it the Lord's Day and, interestingly, some of them called Sunday the eighth day rather than the first day. The eighth day, they said, was the beginning of a new creation (e.g., Letter of Barnabas, ch. 15).

In those early centuries, all the churches kept Passover. They did not keep it like the Jews, with a meal of bitter herbs, but with a communion service because Christ, our Passover, rose from the dead. The Passover is a celebration for the Christian. (Passover has now become Easter, and many traditions have been added to it.)

Some churches kept Passover on the same day as the Jews, Nisan 14, a day based on the Jews' lunar calendar. Most churches, though, took to celebrating the Passover on the Sunday after Nisan 14.

In the early fourth century, Emperor Constantine the Great first legalized, then strongly supported Christianity. Many Roman citizens became Christians, controversy abounded, and a lot of church tradition was confused or lost. The Council of Nicea, which was called and presided over by Emperor Constantine, made it mandatory for churches to celebrate Passover on Sunday. (They did not, however, address the Sabbath at all because there was no controversy about it.) Some astronomical calculations by the church in Alexandria also produced the confusing math that makes our Easter jump around every year.

After, the council, as Christianity became more and more established in the Roman Empire, Sunday was made a legal holiday. It was not long before the old teaching about a perpetual Sabbath was lost, and Christians began calling Sunday the new Sabbath.