Any honest student of the Bible knows the Sabbath is still on Saturday. God created the Sabbath – man made Sunday the Lord’s Day. There is nothing wrong with observing the Lord’s Day - would that we observed everyday as the Lord’s. Observing the Lord’s Day is up to you; but, there is no Biblical obligation to do so. The expectation to set aside Sunday for God is akin to the additional rituals the Pharisees placed on the Jews. You know the ones that Jesus chastised them for. It has become one of the “traditions of men”; and, as in Jesus’ time, these traditions have, for many, supplanted the ordinance of God.
With the Law, Jesus Himself said that the Law would not pass away until this Heaven and this Earth did. Without the Law, we are told in the Old Testament that whatever God does, nothing can be added to it or taken from it – Ecclesiastes 3:14.
People talk about circumcision being a sign in the Old Testament and baptism being a sign in the New Testament. These are signs that show we are God’s children. God says keeping His Sabbaths is a sign that we know He is our God – Ezekiel 20:20. For more Scripture on this issue see this article on my site.
Worshipping and fellowshipping on Sunday is great. But, what are you telling God when you ignore His Sabbath?