There are two worlds, the natural and the spiritual. Both of them have a sun, and either sun is the source of heat and light. But the heat and light from the sun of the spiritual world have life in them; their life comes from the Lord, who is in the midst of that sun. Heat and light from the sun of the natural world, however, have no life in them, but serve as receivers for the two previous kinds of heat and light (as is commonly the relationship of instrumental causes to leading causes) so as to transmit them to mankind. So it must be known that the heat and light from the sun of the spiritual world are the source of everything spiritual. The heat and light too are spiritual, because they contain spirit and life. But the heat and light from the sun of the natural world are the source of everything natural, and these are, taken by themselves, devoid of spirit and life.

Now since faith is related to light and charity to heat, it is clear that in so far as a person is in the light and heat radiated by the sun of the spiritual world, so far is he in spiritual faith and charity. But in so far as he is in the light and heat radiated by the sun of the natural world, so far is he in natural faith and charity. From these considerations it is evident that just as spiritual light is contained within natural light, as it were in its container or repository, and likewise spiritual heat is contained within natural heat, so too is spiritual faith contained within natural faith, and likewise spiritual charity within natural charity. This happens in step with a person's progress from the natural to the spiritual world; and this progress is dependent upon belief in the Lord, who is light itself, the way, truth and life, as He Himself teaches us.

[3] This being so, it is clear that when a person is in spiritual faith, he is also then in natural faith; for spiritual faith is, as has been said, contained within natural faith. And since faith relates to light, it follows that by being so inserted one in the other, the person's natural becomes as it were diaphanous, and that, according to the way it is linked with charity, it acquires beautiful colouring. The reason is that charity shines with a reddish glow, faith with a brilliant white light. It is the flame of spiritual fire which makes charity glow red, and the brilliance of light produced by it which makes faith shine white. The opposite happens if the spiritual is not within the natural, but the natural is within the spiritual, as happens with people who reject faith and charity. In their case the internal of their mind, which controls them when they are left to their own thoughts, is hellish; and they actually derive their thoughts from hell, although they are unaware of this. The external of their mind, however, which controls their conversation with companions in the world, looks as if it were spiritual, but is crammed with the sort of filth found in hell. Consequently these people are actually in hell, being in the opposite state to those described before.