Shadow and Substance: Hold Fast to the Head
Because Christ is sufficient, the Colossians must not allow anyone to condemn them over food, drink, festivals, new moons, or sabbaths, nor disqualify them through self-abasement, visionary claims, or the worship of angels. The calendrical items are called a shadow of things to come, while the substance belongs to Christ. The paragraph ends with the decisive problem: such teaching fails to hold fast to the Head, from whom the whole body grows with God-given growth.
Where this fits in the story: the Old Testament repeatedly groups festival, new moon, and sabbath observances, while later Scripture can speak of earlier institutions as shadows that point beyond themselves. Colossians does not mock the biblical story; it argues that its goal cannot be detached from Christ.