Since we are beings experiencing life as our very own, doubt about spiritual realities such as eternal life, the loving kindness of God, or even that God exists, may sometimes arise. Swedenborg suggests that having such doubts is a normal and important part of our regeneration cycles.

There are two kinds of doubt: affirmative and negative. Affirmative doubt might be expressed something like this: "I don't understand this, but I would like to, and will try to live rightly and seek more understanding". Negative doubt might be more like, "I don't understand this, so I'm going to reject it."

In "A Guide for the Perplexed", by E.F. Schumacher, there's a scene right at the beginning of the book where the author is in Moscow on a tour of the city. He sees a beautiful church ahead of him. He consults his map, and it's not marked there. He consults his Soviet tour guide, who says that the church is not on the map because it's still an active church - not a monument or museum. Schumacher is struck by this -- and extends the thought to be that our maps of knowledge often leave out the important living unanswered questions.

(References: Arcana Coelestia 4099, 5044 [1-13])

5579. When they had finished the eating of the produce. That this signifies when truths failed, is evident from the signification of “produce,” as being truth (see n. 5276, 5280, 5292, 5402); that truth failed is signified by their “finishing the eating of it.” Those who are in the spiritual world are sated with things true and good, for these are their food (n. 5576); but when these have served their purpose, they come again into want. This is as with the nourishment of man by material food when this has fulfilled its use, hunger comes on again. The hunger that is a need of spiritual things, in the spiritual world is evening or the twilight of their day; but after it comes daybreak and morning. Thus there are alternations there. They come into that evening or into spiritual hunger, in order that they may feel hungry and long for truths and goods, which yield them more nourishment when they are hungry, just as does material food to one who is famishing. From all this it is evident what is meant by the need of spiritual things when truths failed.