2853. In thy seed shall all the nations of the earth be blessed. That this signifies the salvation of all who are in good, is evident from the signification of "being blessed," as being to be enriched with celestial and spiritual good (see n. 981, 1096, 1420, 1422); here, to be saved, because spoken of those who are saved (that "to be blessed" has a comprehensive meaning is well known); from the signification of "seed," as being the faith of charity (see n. 1025, 1447, 1610); and from the signification of the "nations of the earth," as being those who are in good (see n. 1159, 1258-1260, 1416, 1849).
[2] Moreover in these words there is contained the following arcanum: that through the church (which is here the "earth," n. 662, 1066, 1067, 1262) those are saved who are out of the church; for as just stated, "thy seed" denotes the faith of charity; and no others are in the faith of charity than those within the church, for the faith of charity is truth of doctrine adjoined to good of life. The case is this: The Lord's kingdom on earth consists of all those who are in good, who though scattered over the whole earth, are still one, and as members constitute one body. Such is the Lord's kingdom in the heavens, where the whole heaven represents one man, which is therefore also called the Grand Man (n. 684, 1276); and what is wonderful and hitherto unknown, all parts of the human body correspond to societies in heaven. And therefore it is sometimes said that some societies belong to the province of the head, some to the province of the eye, others to that of the chest, and so on, which correspondence will of the Lord's Divine mercy be spoken of by itself.
[3] The case is the same with the Lord's church on earth, where the church is like the heart and lungs; while those outside the church answer to the parts of the body which are supported and live from the heart and lungs. Hence it is manifest that without a church somewhere on the earth the human race could not subsist, as the body could not without the heart and lungs (see n. 468, 637, 931, 2054). From this cause it is that whenever any church is consummated, that is, becomes no church because there is no longer any charity, a new one is of the Lord's providence always raised up; as when the Most Ancient Church called "Man" perished, a new one was created by the Lord, which was called "Noah," and was the Ancient Church that was after the flood; and when this degenerated and became none, the Jewish and Israelitish representative Church was instituted; and when this became altogether extinct, the Lord then came into the world, and set up again a new one; and this for the purpose that there might be conjunction of heaven with the human race through the church. This is also what is signified by "in thy seed shall all the nations of the earth be blessed."