In this excellent clip 6-minute clip, Rabbi Dr. Yitzchak Breitowitz explains why the resurrection of the body is an important belief for understanding what it means to be embodied persons.
His main argument is that it is fitting for our bodies, which are the means by which we may perfect our souls through good deeds, to partake of the ultimate reward and communion.
Resurrection, explains Breitowitz, restores the true unity of the person as an image of God who is also One.
Take a look: