So, our rest is spiritual, because our kingdom is spiritual. It is not a physical rest like that of the Jews who participated in a physical and not spiritual realm. The day a Christian should set aside for the Lord, to congregate, worship the Lord and hear the preaching and teaching of the Bible is the first day of the week, the day after the Sabbath. That is, our day is Sunday.

After the Sabbath, at the dawn of the first day of the week, Mary Magdalene and the other Mary came to see the sepulcher. [Mat 28.1; When we meet the first day of the week, we who have new life celebrate the resurrection of Jesus Christ, the source of our new life.