"The essence of belief is the establishment of a habit; and different beliefs are distinguished by the different modes of action to which they give rise."

Next Quote

The Christian and the Materialist hold different beliefs about the universe. They can't both be right. The one who is wrong will act in a way which simply doesn't fit the real universe. Consequently, with the best will in the world, he will be helping his fellow creatures to their destruction.

— C. S. Lewis