Faith is fine. In the financial industry, we operate on good faith all the time. And in science we have faith. The first article of faith is the natural world can be explained in natural terms. Actually the first article of faith is that there is a natural world.
The question is, why do we have faith? Sometimes our reason is a good one, sometimes it is not. To know when a reason is good or not, I turn to the Brooklyn Bridge test. If a man walked up to you and offered to sell you the Brooklyn Bridge, you'd have to have faith that you would become the owner of that Bridge for the price offered.
Whether or not you are a fool depends on why you have that faith.
So let's look at the reasons religious people give for having faith, then apply them.
1. It feels good/right to believe in God.
Apply it to the Brooklyn Bridge salesman. I have faith that this sale will happen as described because it feels good or right to believe this.
Sends off the FOOL alarm.
2. My family/friends/pastor believe in God.
If my family were convinced that this guy was going to go through with the sale and you'd be the proud owner of big bridge, that still makes me a fool for having faith in him. It just means my family are fools too.
3. I would be immoral if I did not believe in God.
If I thought it was immoral not to buy bridges off of salesman- I'd be a fool.
And so on. Now look at the why we might have faith in science, and by extension that the evidence that exists points to a change in species over long periods of time.
->Science has been shown to have utility.
If buying bridges from men had generally had some desireable function - you would not be a fool for buying this bridge...even if conmen existed, as long as the good outweighed the bad this would be a good reason for having faith in something.
There is no good reason for having faith in religion. Faith is arbitrarily assigned to certain matters via tradition or pure reasoning. Sometimes this kind of faith is harmless - if you simply have faith that there is something spooky going on in the universe, a creator spirit of some kind exists. That doesn't necessarily have bad implications. It would be like thinking that you have just won $1,000,000 when a letter comes through the post with colourful writing on to that effect. That doesn't necessarily have bad implications, but you could end up getting conned if you followed through with some of the possible implications of that faith (ring a premium rate number for example).
Faith in religious issues is only really railed against by atheists when it is a faith based belief about the natural world. That we have souls so we can't abort zygotes. That morals are god given and anyone who follows different morals is evil and its ok to treat them like shit. The problem is that faith in souls doesn't look like a terrible thing to believe - a harmless piece of faith...but that same piece of faith plus a little bit of reasoning can lead you to some very foolish and possibly dangerous conclusions
When your faith leads you to making decisions that negatively effect other people, and the reason you have for that faith is based on a foolish reason ('it makes me feel good that we have souls and that souls are precious and that aborting zygotes is evil') - that is when faith is bad.
If you have faith in something for bad reasons, you can end up doing or thinking foolish things. Having faith that there is more to reality than 'I think therefore I am', is not having faith for bad reasons.
™ Version 4.2