Without revelation from the Divine, we cannot know anything about eternal life or even about God, and even less about love for God and faith in God. This is because we are born into utter ignorance and have to learn from worldly sources everything that gives form to our understanding. It is also because by heredity we are born with evils of every kind, which come from love for ourselves and for the world. These loves give rise to pleasures that retain constant control over us and prompt us to think things that are diametrically opposed to the Divine. This, then, is why we know nothing about eternal life; so there must of necessity be some revelation that makes it possible for us to know.
If we consider people in the church, we can see very clearly that the evils of love for ourselves and for the world bring about this kind of ignorance about eternal life. Even though people in the church are informed from revelation that God exists, that heaven and hell are real, that there is an eternal life, and that this eternal life is gained by doing good things that are inspired by love and faith, still they fall into denial; and the educated are as prone to this denial as the uneducated.
This shows how great the ignorance would be if there were no revelation.
So since we live after death and our life after death is eternal, and since the particular life that lies ahead for us is based on the state of our love and faith, it follows that the Divine, out of love for the whole human race, has revealed the kinds of thing
In the Christian world, what the Divine has revealed for us is the Word.
Since the Word is a revelation from the Divine, it is divine in every detail. This is because whatever comes from the Divine cannot be otherwise.
Whatever comes from the Divine comes down to us through the heavens, so in the heavens it is adapted to the wisdom of the angels who live there, and on earth it is adapted to the grasp of the people who live here. Consequently, the Word has an inner meaning, which is spiritual and intended for angels, and an outer meaning, which is earthly and intended for us. For this reason it is the Word that joins heaven and us together.
The true meaning of the Word is understood only by those who are enlightened, and we are enlightened only when we are devoted to loving the Lord and having faith in him. In that case our inner levels are lifted into the light of heaven by the Lord.
The Word in its letter cannot be understood properly except by means of a body of teaching drawn from the Word by an enlightened person. Its literal meaning has been accommodated so that it is possible even for those with no education to comprehend it; therefore [to find their way to a truer understanding] they need a body of teaching drawn from the Word to serve as a lamp.
from New Jerusalem, Sections 249-254