This is a bold assertion. How many of you live each day like you believe in the resurrection of YOUR body? Not a different body -- a different person, different eyes or hair or fingers or voice. YOU. Do you believe you will BE YOU, for eternity, in that very flesh, bone and skin you now wear?
People are confused on this. Have you ever heard a friend ponder, "I wonder if I'll be myself in heaven?" or "I wonder if I'll be a different race?" or "I wonder if I will still be able to run fast/ sing beautifully/sew French knots ... in heaven?" Or the worst EVER: "I wonder if I'll be an angel?" That's rather like asking if you will be a rhinoceros. We won't be changing to another species, thankfully.
For a few days each year, we pound home the resurrection of Christ's body. But let me ask you, Why was it SO important for Jesus to come back to life in his old body, in the very same body in which he was crucified? That's why the nail marks and sword wound were so important; they proved to the disciples that this wasn't Jesus in some new body, or some imposter, cloaked in a familiar face. In those early days, the wounds proved his identity as the crucified Messiah.
But for us, they tell of a bigger truth. Jesus is the "first born among many brethren," the "first born from the dead." Jesus shows us what a resurrected human looks like, acts like. Paul tells us we participate in his death, and in his resurrection. That means that what happened to his body, will happen to our body. Could God the Father have given him a brand new body, one that LOOKED like the old one, but was really new? Could the old, tired, wounded body have been left in that tomb? I suppose -- but God didn't do that.
Because He's a redeeming God. He doesn't give up on the old. He uses it again. He uses us again.
What are glorified bodies like? They are like Jesus's body after his resurrection. They have new, amazing abilities (I believe), that they didn't have before. But essentially, they are the same bodies. It's important that we think of the dead this way, because we must realize that the dead -- including us when we are dead -- are HUMANS. We remain what God created us first to be.