The case for no longer obeying the Fourth Commandment from New Testament Scripture is convoluted and weak!
In 1 Corinthians 16:1-2 Paul instructs the believers there: "Now concerning the collection for the saints, as
I directed the churches of Galatia, so do you also. On the first day of every week each one of you is to put aside and save, as he may prosper, so that no collections be made when I come.” (NASB)
In Acts 20:7, Luke relates a story that begins, "On the first day of the week, when we were gathered together to break bread, Paul began talking to them, intending to leave the next day, and he prolonged his message until midnight."
Although we may deduce from these passages that the early church met together on Sunday (the first day of the week) , we cannot say that they did this to the exclusion of keeping the seventh day Sabbath! In fact, we know that the church continued to keep the seventh day Sabbath until they were forbidden to do so in 325 AD.
Contrary to what most Christians have been taught, the above mentioned passage from Acts does not indicate that they were meeting on Sunday morning as the church does today. It refers instead to the Jewish custom of the last meal of the seventh day Sabbath. By our reckoning this meeting would have started at sunset Saturday with Paul teaching till Midnight Saturday. Paul's intended departure might then have been on what we would reckon as Sunday morning. A correct understanding of this passage actually debunks the doctrine that we don't keep the seventh day Sabbath because the early church didn't do so! There is no way we can justify disobeying the 4th Commandment by either of these New Testament passages. But this does not mean that we should no longer meet together on Sunday. I would submit that we should do both.