What makes one idea worthy of faith, over all the other possible things one could believe in?

If we look at new information with preconceived notions whether scientific or religious, we will try to make the new fit into the mold of our preconceived ideas. If it doesn't fit, we tend to reject it. It takes great discipline to look at each new piece of information through fresh, just, and unprejudiced eyes. The discipline necessary to be unprejudiced and fair isn't too much in style these days as it takes enormous self-restraint and a willingness to accept delayed gratification. I'm sure you've noticed.