20. Anyone who has learned about God's order can also understand that man was created so as to become an angel, because in him order reaches its ultimate stage (see 9 above). In this stage something of the wisdom of heaven and the angels can be formed, and it can be reconstituted and multiplied. God's order never stops half-way, and forms anything there without the ultimate stage; for it is not in its fullness and perfection unless it goes to the ultimate. But when it is there, then it takes shape and uses the means at its disposal there to reconstitute and extend itself, which it does by reproduction. The ultimate is therefore the seed-bed of heaven.

This too is what is meant by the description of man and his creation in the first chapter of Genesis:

God said, Let us make ¹ man in our image, according to our likeness. And God created man in His image, in the image of God did He create him. Male and female He created them; and God blessed them, and God said to them, Be fruitful and multiply. Genesis 1:26-28.

Creating in the image of God and in the likeness of God means conferring on him the whole of God's order from first to last, and so making him an angel as regards the interiors of his mind.

Footnotes:

'The former heavens, which passed away,' as mentioned in Revelation 21:1, signify the societies of people in the spiritual world who were only in external or apparent good. (Apocalypse Explained 675) Heavens are celestial and spiritual things. Consequently, they are inmost things, both of the Lord's kingdom in heaven and in the earth. This also refers to the church, and every individual, who is a kingdom of the Lord, or a 'church.' Consequently, heavens denote all things pertaining to love and charity, and faith grounded in them, as well as all things pertaining to internal worship. In like manner they denote all things pertaining to the internal sense of the Word. All these things are heavens, and are called, 'the throne of the Lord.' (Arcana Coelestia 2162)

(References: Apocalypse Explained 21)