The initial situation or setup is basically Part One of the novel. Here, we get all the information we need to understand the story to come—mostly thanks to Ben Caxton, exposition guru. We learn about Mike's unique childhood and his inheritance fiasco. We find he has powers beyond a normal person's abilities and that he lacks the social knowledge the rest of us take for granted. We also see other people struggling to comprehend Mike's Martian mindset, each doing so in different ways with varying degrees of success.
The real conflict starts when Jill sneaks Mike out of Bethesda hospital. That's the moment Mike becomes a serious threat to the World Federation, even though he doesn't know it. It's also the moment human society begins to really conflict with Mike's Martian heritage: he's suddenly thrust into this new world and has to learn how to deal with such an alien culture. The conflict with the government more or less reaches its own conclusion by the end of Part Two, but Mike's struggle with grokking human culture is just under way. Grok away, Mike.
Things get complicated when Mike starts encountering social situations where he can't rely on the advice and guidance of Jill or Jubal. His self-reliance kicks in at the Fosterite tabernacle when he confronts Digby alone. Once he's feeling independent, further complications arise as Mike attempts to grok humanity by traveling the world and reading libraries worth of books in science, religion, and philosophy. Oh, and he becomes a carnie.
Mike finally laughs and realizes that humor is the only way for humans to share the burden of their painful existence. Pretty deep, right? At that point, he decides he must help humanity by changing it to be more Martian, and he starts a church to further this goal. Hey, it was either that or write a self-help book. This is the turning point—the climax—in Mike's conflict with human society. He will no longer be attempting to simply observe but also interact and shape society into something new.
What are we to do with Part Four, i.e., Ben's visit to the Church of All Worlds and subsequent chit-chat with Jubal? After all, it doesn't fit snugly into the climax or the suspense. One of several ways to look at it is that Ben's journey to the Church of All Worlds serves as a kind of mid-episode, revealing the results of the climax and how they set up the suspense to follow. What do you think?
Certain groups in human society revolt against Mike's church, calling him the antichrist. Mike's church is burned down, and the suspense begins to build. It reaches its height when Mike confronts an angry mob. The conflict between traditional human society and Mike's views reaches a violent conclusion as the mob murders him.
In case it wasn't weird enough for you already, buckle your weirdbelts. Next up, Mike's followers grok Mike in fullness by eating him in the Martian tradition. As is typical of a denouement, the suspense of Mike's death is slowly released. We learn what will become of Mike's friends and disciples. Basically, they all become millionaires with superhuman powers. Not too shabby.
Mike is in the afterlife and getting ready to continue his work to help humanity. Doesn't get much more conclusive than that now, does it?