1. what do you do with Mark 16:9?
2. what do you do with Paul specifically calling Christ “the first fruits”, which Christians have always understood to mean the Jewish feast of first fruits was a type or figure of the harvest which began with the Resurrection of Jesus? this feast was always celebrated on the first day of the week?
3. what do you do with the fact that the Christian Church from the time of the Apostles worshipped on the first day of the week because it is the day Jesus rose from the dead?
4. just curious, if you don’t mind sharing, what is your denomination or faith tradition?
Also see John 19:31. The sabbath of John 19:31 was not the regular weekly one, but the special sabbath of the feast. ("For that sabbath day was an high day"). A special sabbath of the feast, not the ordinary weekly sabbath, which was two days later. (Lev. 23:6-11).