Robin, I think I promised to give you a better post on the passage you brought:
Colossians 2:16-17
16 Therefore do not let anyone judge you by what you eat or drink, or with regard to a religious festival, a New Moon celebration or a Sabbath day. 17 These are a shadow of the things that were to come; the reality, however, is found in Christ.
Sorry, it's taken me so long.

I believe this translation, (as with others as well), to be a poor one that has caused many to misunderstand what our beloved Paul was conveying here.
I think he was cautioning the Colossians not to let their former pagan neighbors teach them regarding the Sabbaths, etc. but to let the body of Christ "judge" them, or teach them regarding these things because these things are important! They reveal the reality that is yet to come!
You may notice, that, in the KJV of this passage that the word "is" has been italicized, which means that it has been supplied by the translators and that it was not in the original text. They also transposed the passage so as to convey their bias as to what they thought it meant.
It, in my opinion, can be better understood with this paraphrase: Don't let anyone, other than the body of Christ, teach you regarding the Sabbath days etc. because these things are 'shadows' of what is yet to come. Therefore, they are important.
This was written well after Jesus had ascended into heaven, and yet these things were "yet to come" in the future. Paul is explaining that the Law of God is important, and is prophetic. We dismiss these instructions to our own "demise", in that we won't understand what is happening. this is evident by the many who do not know God's Law and therefore, have been wrong about their many false proclamations of future events and eschatology. Unless we understand God's feasts, etc., it is easy to misunderstand "future" happenings.
You'll note that the writer of the book of Hebrews declares that there yet remains a sabbath rest for the people of God...one that the author advises that we labor to enter into. It still is true! There yet remains a "rest" for us to enter into. We, in my view, do not get closer to that "rest" by disobeying God's instructions to keep His Sabbaths holy.
Peace, dmatic