Opening scene of Raiders of the Lost Ark. You know it. (If you don't, you above all people are to be pitied.) Indiana Jones has journeyed deep into a cavern deep in the South American jungle. He reaches the place where a shiny idol sits, perched on a weight-sensitive pedestal.
Indy sizes it up. He runs the guesstimated calculations in his head. He pulls out a pouch of sand, feels its weight in his hand, hoping it is equally heavy to the idol grinning back at him. He pours a bit out. He knows the only way to safely dispossess the pedestal of its old affection is the equal weight of a new one. He steels himself. He stretches his arms. Quick as lightning he snatches the idol from its stony cradle while simultaneously putting the sandbag in its place.
There is a pause. Nothing happens. He smiles, turns. And then all heck breaks loose. Actually, the cave breaks loose. A gigantic stone bowling ball comes tumbling down. Poison darts start shooting out of the walls. Pits open up. Walls slam down. And before you know it, Alfred Molina has a wall of spikes through his brainbone.
This is exactly what happens when we try replacing an idol with religious behavior. We think it'll work. But it's just a bag of sand.