Returning to the wrong interpretation of fornication as commonly thought to be a sexual act rather than a metaphor Mat 5:32  But I say unto you, That whosoever shall put away his wife, saving for the cause of fornication, causeth her to commit adultery: and whosoever shall marry her that is divorced committeth adultery.

Firstly note the use of fornication is to do with false god worship in 2Ch 21:11  Moreover he made high places in the mountains of Judah, and caused the inhabitants of Jerusalem to commit fornication, and compelled Judah thereto. Isa 23:17  And it shall come to pass after the end of seventy years, that the LORD will visit Tyre, and she shall turn to her hire, and shall commit fornication with all the kingdoms of the world upon the face of the earth.

Question: Is history relevant to Christians?

1Jo 2:6 “He that saith he abideth in him ought himself also so to walk, even as he walked”.  One cannot understand or reconcile the message of the bible without history or you will end up off track or false teachers will lead you astray, probably to hell. Not all professed Christian leaders speak for God i.e. Aaron and Miriam Num 12:2, Korah numbers 16:32-35.  The Old. T. instructions are the same as the New T.  New T. writers quoted from Deut nearly 200 times. Christ quoted in Matt 4:1-11, Deut 6:13, 16; 8:3; 10:20; Deut 12:8, Judge 17:6, 21:25. 

Question: What is the Sabbath and how is it kept?

It is not another word for rest; but for a period of time, sunset the sixth day (Friday evening) to sunset the seventh day (Saturday evening) (Genesis 1:8). Thus one cannot keep the Sabbath at any other time or day. As that would mean one can move the name around to refer to any time. One cannot move a specific time set by the sun and moon around. So calling any other day a or your Sabbath is anti bible and imposing an imposter similar to that of identification theft of  person!