Resurrection is a Miracle that we must Believe

 Menoras HaMe’or (04:02:03:01) The matter of the resurrection of the dead is not like the reward of the world to come, which is a natural thing for the perfect soul, but it is a matter of miracle and a very wonderful one of the great miracles that G-d has done and will do, and since it is something outside of nature, like the pregnancy of a woman who is born to be barren, and also the rains that come as a reward for a mitzvah... And this is what they alluded to when they said, Rabbi Yochanan said, "Three keys were not delivered by the hand of a messenger, and these are the keys of life, of rains, and of the resurrection of the dead...". Therefore, we must believe that this is one of the great miracles written in the Torah, and that the souls of the righteous will return to their bodies and eat, drink, and beget children. This is a matter outside the nature of reality, and there is no proof for it from rational analysis, but is something miraculous. We must accept it by faith.

Menoras HaMeor (04:02:03:02) All those who deny the Resuerrection of Dead or anyone of the other miraculous matters which are written in the Torah is as if he  denies the entire Torah and he has no portion in the World to Come.