Let us consider a question emailed to me, the answer to which is illuminated through careful study of the original language.
Acts 20:7 in the NIV states that Paul and the disciples met on "the first day of the week," which would be Sunday. This would be somewhat clear evidence of the early church shifting its "worship" focus from the predominantly Jewish Sabbath (Saturday) to Sunday, if we believe that this meeting was a formal "worship service." When I look at the Greek transliteration from the NAS-NIV Greek parallel, it reads "on the first (of the) weeks." The word "day'" is not present, and "of the" is a necessary inclusion. A tract from a Jewish-Messianic group I read argues that the proper translation should be "the first of the weeks." Their understanding is that this day was the first Sabbath of the Feast of Weeks. Whether it is one day or the other is irrelevant to my present day of worship, but I'm curious about the Greek and this translation, as I tend to view the early church as very Jewish and still faithful to Jewish customs as long as they were not preempted by Jesus. -- Dave Lawson (Providence)
It is true that the Greek text of Acts 20:7 is ambiguous. Either it should be translated "on the first day of the week" -- the choice of most English versions, or "on the first [hour] of the Sabbath." As a suggested rendering "the first Sabbath of the Feast of Weeks"