I believe that Jesus did perform miracles. As far as dying for our sins, if that is what he believed he was doing, then yes he did die for our sins. It doesn't matter what I think he died for. He was the one doing the dying.
After I die, I will just return to the universe until I become a part of something else. I think that energy is what makes living things well... living things. I don't believe that my energy will die, just become a part of something else.
Regarding the Bible, there are things I believe have substance. There are too many to list in full. For example, the flood. I believe it was cased by an earthquake in the ocean. This could explain the animals as well as science has shown that they can sense earthquakes and will flee. The earthquake triggered a tsunami destroying everything. How Noah knew to build the ark? Either he was crazy, or knew it was going to happen.