But why Saturday? How do you know that Saturday was the Sabbath when Deuteronomy and Malachi were written?
Because the Jews say that’s when it is, and I follow that Jewish custom.
I do occasionally find myself conflicted with some elements of Torah, such as Urim and Thummim, which I view as soothsaying. Or certain elements of animal sacrifice during the Old Temple period, and its possible restoration in The Temple to come. I try to keep kosher, though limiting it to poultry and fish for similar reasons.
In other words, I sometimes argue with God, which is the original meaning of Israel...as opposed to islam, which is to submit.
It took a long time in many Christian settings to realize that I was much happier with an Old Testament outlook.
Though I realize too that the United States could never have been founded without Christianity, so I recognize that for a great deal of people there is happiness therein too.
What I do lament however, is how many Christians seems to give The Law short shrift believing that the New Testament outlook somehow abrogates The Law. I obviously do not adhere to such a view.