2435. 'That I will not overthrow the city of which you have spoken' means that this being so he would not perish, that is to say, the person with whom the truth which has good within it is present. This is clear from the meaning of 'a city' as truth, dealt with in 402, 2268, 2428. From most ancient times men have argued about which is the firstborn of the Church, whether charity or faith. The reason is that man is regenerated and made a Church by means of the truths of faith. But people who have given preference to faith and made it the firstborn have all sunk into heresies and falsities, and at length have annihilated charity altogether. One reads of Cain, for example, by whom a faith such as this is meant, that he at length killed Abel his brother, who means charity. One reads after this of Reuben, Jacob's firstborn, by whom also faith is meant; but he defiled his father's couch, Genesis 35:22; 49:4, as a result of which he was disgraced and the birthright passed to Joseph, Genesis 48:15; 1 Chronicles 5:1.

[2] This was the origin in the Word of all the disputes, and also the laws concerning the birthright. The reason for this controversy was that people did not know, even as it is not known today, that the amount of faith a person has depends on the amount of charity there is in him, and while a person is being regenerated charity offers itself to faith, or what amounts to the same, good offers itself to truth, and implants and accommodates itself in every part of it, and also in so doing causes faith to be faith. This being so, charity is really the firstborn of the Church, though to man it seems to be otherwise; see also 352, 367. But because these matters are the subject in many places after this, more in the Lord's Divine mercy will be said when those places are reached.