I was a little confused and uncomfortable when you said there is no heaven up there but a new earth in your sermon last Sunday.
Thanks for the clarifying question about where we spend eternity.
Regarding eternity, I suggest Revelation 21. In this passage, the all believers of all the ages (including the church) are symbolically referred to as the New Jerusalem (other passages in Revelation identify the New Jerusalem as all the Believers). Notice, they are coming down OUT OF heaven, to their new permanent dwelling place: the new earth. This appears to be the final destination of God for His people: the new earth.
In fact, I do believe that when we now die, we go to be with God in heaven. But one day, God will complete the work he began in Genesis, returning us to the Garden (the New Earth). It is interesting to note that in Genesis 1, the 7th day never ended, unlike day 1-6. This leads some Biblical Scholars to conclude that we are still in the 7th day of God's creation; it will not be complete until we are completely restored and returned to the Garden.
The only major significance in understanding this passage for me is this: when I come to explaining to pre-christians about spending eternity with God, they get a better feel of why this is going to be so grand if I tell them to picture a new earth with no devastating quakes, storms or people running around sinning and destroying all of God's creation. Imagine a perfect earth. THAT"S our eternal destination. Too often, when people think of Heaven, they think of clouds and harp music. In reality, the ONLY thing we know about heaven is that it is the place where God dwells. (Also, in reality, because God is everywhere present, God will also dwell in the New Earth).
I hope this clarifies my comments on Sunday. Sometime next year I will preach a series from Revelation. I will address the issue in more detail from the pulpit then.
Thanks for the question!