Question: In the Reading in Exodus 20, Verses 8-10, Moses is told to keep the Sabbath, the 7th day, holy. Why do we not honor/follow this?
Answer: Keeping the Sabbath (Saturday) holy and ceasing from work is the 4th of the 10 Commandments given to Moses for Israel at Mount Sinai. Today, we as the Church typically worship on Sunday the first day of the week for the following reasons:
1. All the 10 Commandments are restated in New Testament. As such they are typically reaffirmed, even strengthened, as they are in Matthew 5. In the case of the 4th Command, the New Testament changes it.
Paul says the following in Romans 14:4-6:
"Who are you to judge the servant of another? To his own master he stands or falls; and he will stand, for the Lord is able to make him stand. One person regards one day above another, another regards every day alike. Each person must be fully convinced in his own mind. He who observes the day, observes it for the Lord, and he who eats, does so for the Lord, for he gives thanks to God; and he who eats not, for the Lord he does not eat, and gives thanks to God."
So Paul is teaching that it isn't so much the specific day as long as you have a time for God that you are convinced is pleasing to Him.
2. In the New Testament we have evidence that the day of worship has been changed from Saturday to Sunday because of Jesus' resurrection on the first day of the week (cf. Acts 20:7; 1 Cor. 16:2). In Revelation 1:10, John was worshipping on the Lord's Day.
3. Jesus, who said that He is the Lord of the Sabbath (Matthew 12:8) says in Mark 2:27 that, "The Sabbath was made for man, and not man for the Sabbath." In other words, God established the Sabbath as a rest for His people, not because He needed a break, but because we are mortal and need a time of rest, of focus on God. In this, our spirits and bodies are both renewed.
Israel celebrated the Sabbath on Saturday as a day of rest remembering the greatest thing that God had done up to that time which was the Creation. For us today we are to rest and worship on Sunday, the Lord's Day, the day of the week that Jesus was resurrected from the dead, remembering what is now the greatest thing that God has done - saving us through Jesus' death, burial and resurrection.