Of Course Christians should be keeping sabbath, it is the commandment. It is kind of a Big One... If you have entered into the New Covenant, which is the law written upon you heart by the indwelling holy spirit that you received at your baptism? Hebrews 10. Then you naturally do the commandments. Romans 2 If you are not doing it? then you are a liar and the holy spirit IS not in you. 1 John 2:3-4