There is absolutely no justification for keeping Sunday holy on a weekly basis in the scriptures. God’s other Holy Days may occur on this day, but the first day of the week is just the first day of the week. The Sabbath command is valid for anyone who professes the name of Yeshua Messiah commonly known as Jesus Christ. There is simply no way around it. The Sabbath is mentioned 115 times in the NKJV and not once is it repealed or changed. Jesus Christ wrote the 10 Commandments. Christians are adopted into the house of Abraham and, as such, we worship the same God of Abraham, Isaac, Jacob, and Jesus.
And after these things Paul departed from Athens and came to Corinth. And finding a certain Jew named Aquila, born in Pontus, lately come from Italy with his wife Priscilla (because Claudius had commanded all Jews to depart from Rome) Paul came to them. And because he was of the same trade, he stayed and worked with them; for they were tent makers by occupation. And he reasoned in the synagogue on every sabbath, persuading both Jews and Greeks. (Acts 18:1-4)
This is crucial. Paul worked a normal job and evangelized on the Sabbath, in the synagogue, with the Jews and Greeks. Also, it is very important to note that the book of Acts was written decades after the event described within that book happened. In that light, it is very strange that they never refer to the Sabbath in the past tense, like it was no longer being kept. Think about it.
The Sabbath will be kept in the New Jerusalem (heaven) for eternity. If the Sabbath was kept from Adam to Jesus, and it is going to be kept in heaven, then why not now? And it will be, from one new moon to another, and from one sabbath to another, all flesh will come to worship before Me, says the LORD. (Isaiah 66:23)