[DouglasKC]

Col 1:16 For by him were all things created, that are in heaven, and that are in earth, visible and invisible, whether they be thrones, or dominions, or principalities, or powers: all things were created by him, and for him:
Talk about Scriptural hop-skotch. What exactly this has to do with Jewish holidays I know not.

They're not Jewish holidays. They're God's holy days:

Lev 23:2 Speak unto the children of Israel, and say unto them, Concerning the feasts of the LORD, which ye shall proclaim to be holy convocations, even these are my feasts.

God specifically spells out that these are HIS feasts. They belong to no man, but are God's days. As men, we have a choice: observe them or not.

Since they are God's days, it's obvious that they were created for a specific purpose. That purpose is to help his children learn about God the father and our savior Jesus Christ.

[D-fendr]

What Religious Days Did Jesus Observe?

While He walked on earth, I think that would be the Jewish ones, the ones before the Messiah was the passover sacrifice, before our Saviour's death and resurrection.

Is this where you wish to freeze His Church, and its religious observance? To the point before His sacrifice, before the Lamb of God? Freeze history here and there is no passion, sacrifice and resurrection of Christ and no future of the His Body.

Better to ask "What Religious Days Does the Body of Christ Observe?"