3868. 'She conceived again and bore a son' means spiritual conception and birth from what is external towards things that are more internal still. This is clear from what has been stated above in 3860, where the same words occur. An advance is said to be made from what is external towards things that are more internal still when that advance is from knowledge, which is a property of the understanding, to the will; or spiritually speaking, from truth which is the truth of faith to charity. For the understanding is that which proceeds from the will and gives the will a certain visual form, as faith in a similar way proceeds from charity and gives charity a certain outward form. From this it is evident that the external manifestation of the will is the understanding and the external manifestation of charity is faith. Or what amounts to the same, it is evident that the internal substance of the understanding is the will and the internal substance of faith is charity. Consequently an advance from what is external to things that are more internal still consists in an advance from faith in the understanding to faith in the will, and so from faith to charity - which is represented by 'Levi', dealt with shortly below.

[2] It should be recognized that when distinguished from charity the word faith is used to mean truth, such as the truth of doctrine, that is, such as is incorporated in the confession called the Apostles' Creed. This usage is in accord with the general meaning the word has in the Church, for the belief is that possessing faith in truths constitutes the faith through which salvation comes. Few know that faith is trust and confidence, and among these few fewer still know that trust or confidence originates in charity and is unable to exist with anyone who does not possess the life of charity.