Every Christian I've ever known has said that the physical bodily resurrection of Jesus is paramount to their belief. It's not enough that he rose spiritually, conquering death figuratively, but he has to have defeated death and risen with his body. And it is with his body that he went up to heaven. This is key. He took his physical body with him.
Now, heaven is a place outside of our physical universe so since Jesus didn't just "poof" out of this universe and into an alternate reality of milk and honey and 72 virgi...er, uh my bad--but instead lifted off of Earth to go to heaven I postulate that he had to travel to the "edge" of our physical universe in order to get into heaven.
So that means he had to take all his mass with him as he headed to heaven which puts a physical limit on how fast he could go to get there--or maybe he converted his mass to light and then went the speed of light all the way to get to heaven. The "edge" is something like 13.7 billion light years away and getting farther away as we speak. That would mean that Jesus would need quite a bit more time to get to heaven--something like 14+ billion years--before he could even contemplate physically coming back for act two. I'm sure that he'd want to spend a few million years saying hi to dad and catching up on the heavenly gossip, and all.
So I'm going to go out on a limb and predict that Jesus will return on August 10th, 30 billion years from now, what with factoring in expansion and gettin' through customs at Heaven's border.
Mark your calendars!