…if we allow the Bible to interpret itself, the fact that these religious observances were shadows of things to come would have to refer to the Jewish ceremonial system…
It has been recognized by Bible commentators for many years that Paul was attempting to correct certain Gnostic practices, which had crept into the church at Colossae.
The ceremonial ordinances, whether new moons, feast days, or yearly sabbaths (these yearly sabbaths were “beside the sabbaths of the Lord,” Leviticus 23:4–38), were all shadows of things to come,