We may conclude that heaven is from the human race from the fact that angelic minds and our minds are very much alike. Both enjoy abilities to understand, perceive, and intend. Both are formed for the acceptance of heaven. In fact, our minds are just as wise as angelic minds; but they are not as wise in this world because we are in an earthly body, and in an earthly body our spiritual mind thinks in a natural manner. It is different, though, when it is freed from its tie to the body. Then we no longer think naturally, but spiritually, and when we think spiritually, we think thoughts that are incomprehensible and inexpressible to a natural person. This means we are as wise as angels. We may gather from this that our own inner person, what we call our spirit, is essentially an angel (see above, Section 57).
Once it is freed from the earthly body it is in a human form just like that of an angel. (On angels being in perfect human form, see Sections 73–77 above.) However, when our inner person has not been opened upward but only downward, then we are in a human form after we are freed from this body, but it is a frightening and diabolical form because it cannot look upward toward heaven, only downward toward hell.
from Heaven and Hell, Section 314