First, I am not an expert, nor am I anything but a born again believer who observes the Sabbath. This is a bit of my understanding of why I do so. Your mileage may vary. There is a lot to unpack, and the Sabbath is not something that was given only to Israel. The fourth commandment calls for people to remember the Sabbath to keep it holy. The word remember in this commandment is the only time it appears in the Ten Commandments, meaning that it must have been known beforehand. In this case, Exodus 20, it is, in fact the Israelites who were being addressed, but that is not where the observance of the sabbath began. It goes back to creation where God sanctified and blessed the seventh day of the week as a day of rest; it's the only day for which He did this. It was observed by many who weren't Jews (Abraham, Noah, pretty much everyone up to Jacob, were not Jews), a long time before the Jews came along. It was even observed by the Jews themselves before they received the Law as given by Moses, as can be seen in the gathering of the Manna and the instructions relating to that event. That being said, the Ten Commandments are for all of us, not simply for the Jews, or the Israelites. While I agree with you that Jesus did fulfill the law, I don't think that means that we can go about breaking it at will as we see fit. The stone tablets on which the Ten Commandments were inscribed by the finger of God were placed inside the Ark of the Covenant; the ceremonial, or Levitical law was not, it was on the outside in a pouch. When the veil was torn at the time of Jesus death, the Levitical law was done away with as a foreshadowing of what was to come, and had, at that time come in the form of Jesus' life and sacrifice. There are several places in the New Testament that show that the Apostles continued to keep the Sabbath, as well as references to it being applicable today. Considering that it is one of the Ten, and in those ten are laws against murder, theft, adultery, covetousness, blasphemy, lying, idolatry, and that those also still apply, it doesn't make a lot of sense for a "well, except for this fourth commandment." No one would make the argument that Jesus' fulfilling of the law makes murder, adultery, theft, lying, or the others okay to do, why is the fourth commandment considered trivial or disposable? Unless one agrees that the Vatican and the Papacy had the authority to make the change from the seventh day of the week to the first day of the week, it's really not possible to make the argument that there was any authority at all to make that change. For me, the Sabbath is something I keep. I don't keep it to earn my righteousness or salvation, I do it out of gratitude, and I have to say I find much blessing and rest in doing so. It's not for me to judge anyone who disagrees with me, nor do I wish to pretend that I'm somehow now Jewish for doing so. It's something I was convicted about several years ago, and since I reject the authority of the Papacy and the Catholic church, I couldn't justify not keeping it. I imagine that my response might make me a target, but whatever. If my skin was thin, I wouldn't be on Poal.