The title sounds like a form of torture, but all I have in mind is a key portion of Trinity & Process (T&P) that I think distills the heart and soul of Greg’s thesis in a few pages. If you could only read a few pages and wanted to get Greg’s main point, I’d suggest the section under the section A Critical Evaluation And Trinitarian Reconstruction Of Di-Polar Theism on pp. 43-53 of the summary document linked to in the previous post. I hate to say that 10 pages could get it, but these short pages come closer than any other brief selection of the book to expressing Greg’s thesis. That’s not to say you don’t need everything leading up to p. 43 to appreciate the logic or everything that follows to fill out the arguments. But if you want the briefest CliffNotes on T&P, pp. 43-53 will do it.
And once you appreciate what Greg says in this brief section you’ll understand why kenoticism and passibilism of the sort Greg advocates now are, strictly speaking, logically impossible (given T&P that is). It’s right there.