First, the word "
alike" is in italics because it is not in the Greek. There is nothing wrong with esteeming every day, after all, Yahweh made them all. If we choose to worship Him seven days a week, so be it and halleluyah! However, that does not change the fact that as we worship Him every day we must also rest from labor on one day, the Sabbath. It is a mistake to read the Sabbath into this passage. Nowhere is the Sabbath mentioned. Nor can we read any of Yahweh's annual sabbaths or feast days into this verse. There were many other "days" that the Jews highly esteemed besides the Sabbath and feasts. For example, most Jews at that time fasted twice a week (
Luke 18:12 and Talmudic writings). The Jews also kept fast days throughout the year as mentioned in
Zech 8:19. Then there was the Feast of Purim (
Esther 9:28), and the Feast of Dedication or Hanukkah (
John 10:22).
The Jewish converts would have probably continued esteeming these days whereas the Gentile converts would probably not, especially since they were not commanded by Yahweh to be kept. However, all men knew the Sabbath was commanded and so there was no question about its observance as seen in such verses as
Acts 18:4 and
Acts 13:42-44;
14:1.