A friend of mine, who'll be a future guest blogger for this site wrote a piece I've excerpted below:
What does it mean to "believe" in something? My academic background is in psychology. I know what it means to "think" something. But that has to be different from what it means to "believe" something, especially in a religious sense.
If to "believe" is to "think," we have some real problems. I have asked different people who say they "believe in God" or "believe in Christ" or "believe in salvation" or "believe in the virgin birth" or "believe in justice" what they think about these things, and they have produced more answers than there were respondents.
I've been told that Catholics "believe" one thing and Methodists another, but when I ask what they think, there is great variety within, and overlap between, those groups. Because two people use similar words for what they believe does not mean they think the same things but it does somehow indicate a shared.. something.
I'm hesitant to equate belief with thought because I know my thoughts change day to day, even minute to minute. But I still believe. Belief seems more active, more about the overall direction I'm facing, the life I'm living, the experience I'm having. It might incorporate some cognitive elements, but it seems far more behavioral and affective.