There is, for everyone, a crossroads when it comes to spiritual things, a basic decision to be made. Are you going to believe in the Lord and in spiritual reality? Or are you only going to believe what you can see, touch, feel and otherwise "know" from your own mind? The Writings say those who choose the latter course are closing themselves off from the truth, because by definition spiritual reality cannot be seen, touched, felt or otherwise "known" through purely human means. That's what it means to eat "of the tree of the knowledge of good and evil," and it leads to spiritual death – which is being cut off from the goodness and truth the Lord wishes to bestow on us.

The people of the Most Ancient Church were in a state of love to the Lord, and had been invited to gather all the wisdom and knowledge flowing from that love – the fruit of all the other trees. But they had to accept the Lord as the source, had to accept that He existed, had to accept that He was infinite and beyond their finite understanding. To think otherwise – to think that through their own minds they could explain the Lord – would be to put themselves above him, and lead them into evil.

It's worth noting that this was not a call for people to shut down their minds. The fruit of the other trees represents an incredible bounty of exploration, learning and wonderment. And we're not called on to shut down our minds today; the Lord gave us our intellectual faculties for a reason. To let the Lord in, though, we have to accept the unprove-able idea that He is love itself and reality itself, and see all other knowledge in that light.

(Referencias: Arcana Coelestia 126-132, 127, 128-134, 129, 0130)

128. The worldly and bodily-minded man says at heart, Unless I am taught about faith and about things that belong to faith by means of sensory evidence so that I see for myself, that is, by facts so that I understand for myself, I am not going to believe. And he confirms himself in this attitude from the consideration that natural phenomena cannot be at variance with spiritual. Consequently it is from sensory evidence that he wishes to learn about heavenly and Divine matters. But this is no more possible than for a camel to pass through the eye of a needle. The more he wants by this method to become wise, the more he blinds himself, until in the end he believes nothing, not even in the existence of anything spiritual or in eternal life. This arises out of the basic assumption he makes. This is eating from the tree of the knowledge of good and evil. And the more he eats of it, the more dead does he become. But the person who wishes to be made wise not from the world but from the Lord says at heart that he must believe the Lord, that is, those things the Lord has spoken in the Word, because they are truths. This is the basic assumption of his thinking. He confirms himself by means of rational, factual, sensory, and natural evidence. And things that are not confirmatory he sets aside.