You certainly don’t need complete trust or confidence to believe in the results of science. Sometimes, when people say “science requires faith”, what they are trying to get at is the idea that scientists have to rely on assumptions that they can’t prove. It’s easy to see why science seems like just some wacky new belief system that you have to have faith in to believe. The difference is, if you don’t believe it (and you’re properly motivated), then you can go out and test it. If you don’t believe it (and why would you?