I think it's not unreasonable to accept a man named Jesus lived during that time in Palestine, although actual historical evidence is scant, and Jewish rabble rousers were a dime a dozen, it's not much of a stretch to say he existed.
As for all of the "miracles" -water walking, healing, raising from dead, etc.- there is absolutely no evidence or good reason to take those claims seriously. Just becuase something is written down, doesn't make it so. Just think about the amounts of supernatural claims that have been written since recorded history by every ethnic group every existed/ing, and how easy it is for you to dismiss their claims, so too I dismiss the claims of christianity.