Firstborn, in a supreme sense, represents the Lord as to divine celestial love, and also peope who were of the celestial church. The sanctification of the firstborn, as in Exodus 13, signifies faith in the Lord. The firstborn, in the spiritual sense of the Word, is good, for with infants the good of innocence is first infused by the Lord, by virtue of which man first becomes a man. Since good is of love, and man does not reflect upon his own love, but only upon the thoughts of his memory, and since good has not at first a quality, but acquires one when it is formed in truths, and without a quality nothing is perceived, hence it was unknown that good was the primary principle, or firstborn. Good is first conceived from the Lord in man, and is produced by truths, in which good is manifested, in its own form and effigy. Firstborn, as in Psalm 89:28, signifies the Lord's humanity.

344. Then I saw another angel ascending from the rising of the sun. (7:2) This symbolizes the Lord providing and moderating.

The angel here means the Lord in respect to Divine love, because he ascended from the rising of the sun, and from the rising of the sun or from the east means from Divine love. For in the spiritual world the Lord is the sun and the east, and He is called that in respect to that love. His providing and moderating is apparent from His commandment to the four angels not to harm the earth and sea till the servants of God had been sealed on their foreheads.

That in the highest sense an angel means the Lord's Divine humanity is apparent from the following verses:

...the Angel of (Jehovah's) presence delivered them because of His love and His clemency. He redeemed them, and took them up, and carried them all the days of eternity. (Isaiah 63:9)

The Angel who has redeemed me from all evil, bless (them). (Genesis 48:16)

The Lord, whom you seek, will suddenly come to His temple, even the Angel of the covenant, whom you are desiring. (Malachi 3:1)

...I send an Angel before you to keep you in the way... Beware of his presence...; for My name is in the midst of him. (Exodus 23:20-23)

"Angel" and "one sent" are, in Hebrew, the same word. That is why the Lord so often calls Himself one sent by the Father, meaning by it His Divine humanity.

In a relative sense, on the other hand, an angel is anyone who accepts the Lord, whether in heaven or in the world.