There is some intense irony about the Gom Jabbar. Spoilers for all the books (all six of them), fyi.

In the first book, Reverend Mother Gaius Helen Mohiam talks about humans and nonhumans in the context of the Gom Jabbar. Particularly, she states that the nonhuman thing to do would be to free yourself from a hunter's trap, to save yourself from immediate danger, whereas the human thing to would be to wait for the hunter to return in order to eliminate a threat to the species. The human thing to do is the thing that looks out for the collective survival of the species.

The only issue is that the Gom Jabbar test is administered by nonhumans for nonhumans, and the first "real" human was the only person to lose his humanity: Leto II.

The Bene Gesserit, while able to look ahead and make plans reaching far into the future, were relatively shortsighted. Their goal was the preservation of themselves, generally through their breeding program, Missionary Protectiva and their behind-the-scenes political manipulations. They were acting, collectively, like the animal who chews off his leg to escape the trap. What they didn't do is realize that they are dependent on the ecosystem they live in. They needed to focus on the survival of all of humanity, not just themselves. Leto directly criticizes them for this nonhuman behavior in one of my favorite scenes in the entire series, when Odrade visits Sietch Tabr:

I bequesth to you my fear and loneliness. To you I give the certainty that the body and soul of the Bene Gesserit will meet the same fate as all other bodies and souls. What is survival if you do not survive whole? Ask the Bene Tleilax that! What if you no longer hear the music of life? Memories are not enough unless they call you to Noble Purpose! Why did your sisterhood not build the Golden Path? You knew the necessity. Your failure condemned me, the God Emperor, to millennia of personal despair. My words are your past, my questions are simple: With whom do you ally? The self-idolators of Tleilax? With my Fish Speaker bureaucracy? With the cosmos-wandering Guild? With Harkonnen blood sacrificers? With a dogmatic sink of your own creation? How will you meet your end? As no more than a secret society?

The human thing was not to ensure their own survival, but the survival of humanity through the Golden Path. The Bene Gesserit failed the Gom Jabbar test. Moreover, their collective memories told them the necessity of the Golden Path, and they ignored it. In saving themselves, they doomed themselves and everyone else.

Paul also failed the Gom Jabbar test. Since the Bene Gesserit were too selfish to build the Golden Path, someone else had to. Perhaps their Kwisatz Haderach, one with both past and future memories? Paul knew, even more than the Bene Gesserit, what the Golden Path was and how to build it, but Paul was scared and had drives other than the Golden Path. He could not sacrifice who he was in order to save humanity.

The only reason Leto was able to be the first to pass the test is because he was (ironically) an abomination and because of Paul's failure. Leto was no one and everyone. Unlike Paul, who was someone and had himself to lose, Leto was no one and the sacrifice of millennia of despair was not as fearful. The only issue is if, just as the Baron drove Alia into madness, one of his past memories taking over him, making him be someone with something to lose. The inner Paul, however, helped Leto keep the masses at bay so that he could remain no one. Because he knew at a very early age what he must do, and because he did not develop the same selfish flaws that Paul was able to before awakening the past, Leto was able to be the first human by giving up his humanity. Leto had all the knowledge that Paul and the Bene Gesserit had, without any of the unhuman flaws.

In the end, everything in Dune is about the Golden Path. The books talk about the need (books 1-3), the nature (book 4) and the realization (books 5&6) of the Golden Path. The opening chapter of book 1 is about the Bene Gesserit talking about the need for the Golden Path, without doing it, and book 6 is about the Bene Gesserit finally passing their own Gom Jabbar by accepting their mantle as guides to the Golden Path. I feel that whatever might've happened in Book 7, we would see this laid out more explicitly.

(This is also the biggest flaw in Brian's work. He loses the focus on the Golden Path and just makes it adventures in space with giant worms. Frank passed the Gom Jabbar, Brian did not.)