From Justin Taylor's blog:
John Piper writes:
I have recorded a section of Jonathan Edwards' sermon on Romans 2:10. It lasts about seven minutes. The reason I recorded it is that I regard this
section as the best thing I have ever read on the issue of varying degrees of reward and happiness and holiness in heaven. It is vintage Edwards. He has thought this through in an amazing way. It opens our eyes to the possibilities of heaven that we have never thought of before. If you want to read and ponder it for yourself, it comes from page 902 of the second volume of The Works of Jonathan Edwards.
O that more and more pastors and people would linger over the glorious truths of Scripture until they open like this.
For more on Edwards on heaven, I'd recommend Sam Storms's talk at the 2003 DG conference:
Joy's Eternal Increase: Edwards on the Beauty of Heaven.