why do some christians insist the sabbath should be considered as a holy day?

The first Christians were Jews and they faithfully observed the Sabbath as a holy day just as Christians who desire to not violate the Ten Commandments continue to do.:applause:

Like many "good" religious people , they chose what they like from their holy book. I bet those same Christians ignore that shrimp is abomination, same as with their other brethren ignore than their bible forbids fornication,sodomy with a woman and lies. but all of them get upset over gay sex.

Instead of sticking to an ancient book written by some ignorant ancient middle-easterners , how about you ditch it altogether, or create your own if you so want a fiction book.