“So also faith, if it is unaccompanied by obedience, has no life in it -- so long as it stands alone.” (James 2:17 WNT)
Too many people think of religion, and particularly Christianity, as a matter of having to believe impossible things. Faith and belief are related, but they are not the same things. I can believe all kinds of things (dogs are better than cats, angels have wings and stand by my bed at night, or even that God exists), that make little or no practical difference in how I actually live my life.
Faith, on the other hand, is a matter of personal investment. Faith usually implies belief, but it also assumes that this belief makes a profound difference in how I treat others, engage the world, or spend my time and money. Faith moves me to risk, sacrifice, grow, and challenge. Believing is easy; it requires nothing much of us. But having true faith is the hardest thing in the world. Interestingly, many people report that they don't really know what they believe until they begin to act on faith.
-- Clifton F. Guthrie in “Faith: Living a Spiritual Life”