YES, Sabbath day is on Saturday. So why don’t Christians worship on that day?
God’s covenant with Abraham was based on Abraham’s faith and circumcision on the 8th day was the outward sign of this covenant. Read Genesis 17 but pay special attention to verse 9 to 14. God’s own part was that He would make Abraham into a great nation and that through Abraham’s seed (Jesus) the whole world would be blessed -Gen 26:4 and Gen 28:14. That was it, no laws given, no Sabbath day given to Abraham to keep, because Abraham feared God and had faith in Him and it was credited to him as righteousness.
Fast forward many hundreds of years later, the Israelite are in the desert and God decides to test them. He gives them manna and quail to eat but instructs them not to pick any on the 7th day. It wasn’t a law then but just an instruction which He gave solely to test if they would obey Him (just like He tested Abraham) but they didn’t obey (Exodus 16 pay attention to verse 24-30). Therefore God made an additional covenant with them and this time He added the laws to keep them in check until Jesus came (the seed of Abraham), until He could fulfill the promise to Abraham. Read Galatians 3:19. This time the sign that they were in another covenant with God was for them to keep the Sabbath day (Exodus 31:12-15) something they couldn’t keep as an instruction during the manna test . They even started breaking the covenant when Moses went to the mountain to get the written confirmation of the law on tablets. But in order to move on, God introduced the forgiveness of sins through the blood of a lamb. Years and years God kept sending messengers to warn them when they deviated but they continued to sin. Prophets such as Jeremiah and Ezekiel prophesied that God longed for the day when He would make a new covenant with the Israelite (Jer 31:31-32) which would make the old covenant obsolete because He would have fulfilled His promise and covenant to Abraham that His seed would save the world. (Hebrew 8:13). Also read Galatians 3:23-25. Once Jesus came, God was off the hook, so to speak. The promise had been fulfilled. There was no more need for the old covenants.
Jesus made a new covenant with everyone (baptism qualifies you to enter into this covenant as opposed to circumcision) and interestingly enough Christ did everything that Moses did when he established the covenant. He also shed His blood for the forgiveness of sin, which He knew that we as stubborn people would continue to commit (Matthew 26:28). All we need to do is repent, forgive others and then ask Him to forgive us. As part of this covenant He said the one outward sign He required of us was to love one another. Read John 13 but pay attention to verse 34 and 35. Note that the sign of the covenant was not “keep the Sabbath” like the old covenant that was broken. Everything owed to that covenant/law was fulfilled.
So, are you obligated to circumcise on the 8th day? Nope. If you want you can but not as a law or as a sign of a covenant because that covenant no longer exists and most of us are not direct descendants of Abraham anyway. We are now circumcised in the heart by believing in Jesus. But there are even health reasons why you probably should.
Is it a sin if you worship on Sunday instead of the Sabbath day Saturday? Nope. That was the sign of the old covenant, but its not a sin if you do. Why do I say its not a sin if you do? Because the Sabbath law actually forbade people from leaving their house, cooking, picking food, etc and Christ freed us from that law and the curses for breaking it, so that we can feel free to worship Him even on Sabbath. But it doesn’t matter if you go to church on Saturday or Sunday. It’s the same thing. However, early Christians worshiped on Sundays because Christ rose from the dead on a Sunday and appeared to His apostles on a Sunday. He allowed them to worship Him on a Sunday, taught them and ate with them on a Sunday and that was why the early Christians chose Sunday as their day of worship. Finally, this first day of the week (Sunday), called the Lord’s day, is the day the Holy Spirit came upon the apostles to birth the church. Peter first preached His first sermon on a Sunday.
But Christ seriously wants us to know that going to church on Saturday/Sunday just so that you say you went to church, is still the lesser righteousness which Christ compared to that of the Pharisees. A higher righteousness exists. Ultimately God wants us to have the same faith, obedience and righteousness from within that isn’t based on laws written on stones. If only we can be like Abraham.
Hope this helps someone out there who is torn by this whole Sabbath thing.