Lord of the Sabbath
For the Son of Man is Lord of the Sabbath. Matthew 12:8 niv
So the Son of Man is Lord even of the Sabbath. Mark 2:28 niv
Then Jesus said to them, “The Son of Man is Lord of the Sabbath. Luke 6:5 niv
The Fulfillment of the Law
17 “Do not think that I have come to abolish the Law or the Prophets; I have not come to abolish them but to fulfill them.
18 I tell you the truth, until heaven and earth disappear, not the smallest letter, not the least stroke of a pen; will by any means disappear from the Law until everything is accomplished. Matthew 5:17-18 niv
He did not come to “destroy [dissolve, overthrow or demolish] the Law or the Prophets.” Jesus said that He came to fulfill His purpose as our Savior, not to change or eliminate any of the laws that regulate our relationship with God and with each other. He stated emphatically that not even the smallest letter of the law (jot or tittle) would pass away before His entire plan was fulfilled.
Prophecies of end times in the books Daniel and Revelation, are not completed.
“Now on the first day of the week, when the disciples came together to break bread, Paul, ready to depart the next day, spoke to them and continued his message until midnight.” Acts 20:7 niv
By Jewish reckoning a day begins at sunset. So the phrase “first day of the week” used in this verse can refer to the time beginning at sunset on what we would refer to as Saturday night. Since it was after dark, there were “many lamps” in the upper room. Acts 20:8 niv
1 Now about the collection for God’s people: Do what I told the Galatian churches to do.
2 On the first day of every week, each one of you should set aside a sum of money in keeping with his income, saving it up, so that when I come no collections will have to be made.
1 Corinthians 16:1-2 niv
This was a special offering for the believers in Jerusalem which were living in hard times.
3 Then, when I arrive, I will give letters of introduction to the men you approve and send them with your gift to Jerusalem.
4 If it seems advisable for me to go also, they will accompany me. 1 Corinthians 16:3-4 niv
In verse 3 & 4, it is an offering for the welfare of believers in Jerusalem. It makes no reference to a change of day to worship.