The current heaven & earth have been tainted by sin, so they must be destroyed (2 Peter 3:10). The current heaven (where God is and where saints are) is NOT our final destination. It is a beautiful garden, it is paradise, but it is not where we will live forever. The future heaven isn't really heaven at all ... it's a city (New Jerusalem), 1,500 mi sq. - that's HUGE! It's the distance from Boston to Miami and from Denver to Charlotte. What's more, it's taller than the orbit of most space-craft! In total, it will have 12 separate levels, which God brings down to a new earth.