I think greeny's mistake is in believing that God is intangible (like love) and/or invisible, available through no path other than faith.
I wonder how many people believe what the periodic table of the elements says, for example that Carbon has 12 nucleons. Have you done the experiments? Do you believe everything you read in a science textbook but not believe everything you read in a history book or scripture? Why is that? I think it's because the statements made in a science textbook are at least internally consistent and if the bible, for example, were internally consistent then it would be harder to ignore. There is blind faith in science, logic, and religion.
I am, for better or for worse, eternally skeptical.
I constantly consider the possibility that all my truth is a lie. It erodes the confirmation bias that I exhibit. These lines apply to me at all times, even when I think I've got it; especially when I think I've got it.
With relative perfection, it seems to be a fact that there is always the temptation to go to the other side. Eve was not prepared to face the temptation of an unknown promised to be even more pleasure. The promise of pleasure is very alluring to humans. Anything to keep us alive and on planet Earth.

It is curious that every omniscient being knew that Eve was going to decide that the only way to get rid of temptation is to give in to it. Every omniscient being knew that mankind's faith that Jesus' act of sacrifice leads to salvation would waver in the future.
It's all part of the plan.
Truth has an enslaving quality to it. If it got out that "God exists" is a true statement, then humphreys would be a slave to the facts, even though that truth would probably make him unhappy... He stated that he values truth over happiness and that's good because truth is rarely pleasure. They say that truth sets you free but it actually confines. Many people would be happy to be a slave to truth, in keeping with the spirit of the thread. I myself am, ultimately, a slave to truth but I see and am drawn towards a different light.