“How does the Sabbath law or the Old Covenant translate into New Covenant Christianity? I read that the Catholic Church changed the Sabbath from Saturday to Sunday. Is that true?”
This has been a struggle for many Christians over the centuries. It comes from our sincere desire to obey God and please Him.
Some will say that the Catholic Church instituted the tradition of Christians worshipping on Sunday rather than Saturday. On one hand, it is true, that the "Catholic Church" did meet on Sunday rather than the typical Jewish Synagogue day being on Saturday (Sabbath). I say “Catholic Church” in the sense of the universal Church—“catholic” means “universal”—on the other hand, this is not referring to the Roman Catholic Church. But why did they meet on Sunday rather than on the Sabbath? In the early Church (during the time of the Apostles) they saw Sunday as significant in that Jesus rose from the dead on the first day of the week and so this is when they began to gather.
How do we know this?
Paul, when writing to the Corinthians, in First Corinthians 16:2 told them to set aside their offering on the first day of the week so he didn’t have to do a special collection when he came. Also Acts 20:7 tells us that they gathered together on the first day of the week to break bread. Because the resurrection happened on Sunday, that day was traditionally referred to as “The Lord’s Day” not the Christian Sabbath day (John refers to this in Revelation 1:10). Christians didn’t move the Sabbath day, nor were they seeking to keep the Sabbath in the way that their Jewish brothers did.
Also, Pliny the Younger, an ancient Roman magistrate, wrote about the worship of the Christians and he said, “They gather early in the morning on the first day of the week and sing songs to Christ as to a God.” This was the practice of Christians in the first century.
Under the New Covenant, Christian diet changed, their worship changed, they died to who they had been and they were born again. The first time the idea of how Christians should view the Old Covenant was brought into question when the Gentiles became part of the Church. Peter was told by the Lord to eat some strange things! Unclean things! The Lord’s point was that He was opening the door to the Gentiles (Acts chapter 10.)
Once the door was open to the Gentiles, a lot of things came into question. Do the Gentiles have to keep the law of Moses to be saved? Do they have to be circumcised, do the sacrifices, observe the Sabbaths and the Holy days? This question was brought to the Church in Jerusalem (Acts 15). Many were saying that, “Yes, the Gentiles need to become Jews in order to be saved”. Peter reasoned, “Why do you test God by putting a yoke on the neck of the disciples which neither our fathers nor we were able to bear?” James, then, being the leader of the Church there, said, “Therefore I judge that we should not trouble those from among the Gentiles who are turning to God, but that we write to them to abstain from things polluted by idols, from sexual immorality, from things strangled, and from blood.” (Acts 15:19, 20).
We have to understand that this wasn’t a new “Christian Law” but rather guidelines to follow so that they would live pure lives and not offend the Jews. Is it wrong to keep the Sabbath? No, but it can be dangerous if you keep it believing that somehow God is requiring it of you or that by keeping it you can make God happy with you. It is a good idea to take one day in 7 to worship and rest. Most Christians fulfill that on Sunday and that is OK.
So how should a Christian view the Sabbath? Paul wrote, “And you, being dead in your trespasses and the uncircumcision of your flesh, He has made alive together with Him, having forgiven you all trespasses, having wiped out the handwriting of requirements that was against us, which was contrary to us. And He has taken it out of the way, having nailed it to the cross. Having disarmed principalities and powers, He made a public spectacle of them, triumphing over them in it. So let no one judge you in food or in drink, or regarding a festival or a new moon or sabbaths, which are a shadow of things to come, but the substance is of Christ.”
In the book of Hebrews Chapter 4 the author argues that the Children of Israel wouldn’t enter into the rest that God intended for them. The Sabbath couldn’t bring rest, entering the promise land couldn’t bring rest, and so “there remains a rest (sabbath) for the people of God.” He concludes that rest is putting our trust in Jesus -- that Jesus is our Sabbath. Isn’t that amazing?! Jesus our true rest that God instituted clear back in Genesis!