(Note: I don't often go to the same source twice in a row, but, look who I'm quoting!)
The worship of the golden calf is a self-generated cult. When Moses stays away for too long, and God himself becomes inaccessible, the people just fetch him back. Worship becomes a feast that the community gives itself, a festival of self-affirmation. Instead of being worship of God, it becomes a circle closed in on itself: eating, drinking, and making merry.
Benedict XVI, Spirit of the Liturgy.