I feel blessed to have read this discussion over my morning tea today. Thank you all for this wonderful conversation.
I have been a Sabbath keeper my entire adult life. 23 years if memory serves me. It's been lonely for much of that, as the people around me have not been Sabbath keepers. I have learned to accept the peculiar nature of that life, as it certainly separates me from nearly everyone around me. (1 Peter 2:9)
This is a really great article:
What is the Seal of God? - Bible Revelation Keeping of the law is the "mark of Yah." It is his law sealed into our heads that sets "His People" apart from the people who follow the Whore of Babylon.
My answer to the stated question; "why so much hatred?"
By the very act of keeping the Sabbath, a believer makes non-Sabbath keepers wrong. That is true of all of the set-apart behaviors of the Yehudim, or Netzrayim. Many believers do not eat unclean meat, do not keep unclean feasts, and do not wear mixed clothing. Not as an act of works to get into heaven, but in a humble desire to be as pleasing to the King as possible. By committing these acts, these believers reflect back the true will of our Father, and shine a light on the sinfulness of Sun-day keepers. By keeping the law, they are revealing the wrongness of what mainstream believers are doing. I'm probably not saying this very well. No one wants to be told they are doing wrong when they have been told and live in certainty that they are right. It's very humbling to realize that one's behavior, which was thought to be holy, is actually profanity in the eyes of your God. It's hard to admit to being lied to, and harder still that we believed the lie.
Humble thyself in the sight of Yah, and he shall lift you up. Amen.