Revelation 22:16

I Jesus have sent mine angel to testify unto you these things in the churches. I am the root and the offspring of David, and the bright and morning star.

1. Since the angels belong to God, how could Jesus send HIS angel?  The answer:  He must be God.

Of Jehovah, we read:
Psalm 104:4 Who maketh his angels spirits; his ministers a flaming fire:
Psalm 91:11 For he shall give his angels charge over thee, to keep thee in all thy ways.

The angels are called “angels of God”:
Hebrews 1:6 …And let all the angels of God worship him.

2.  Since God is the One who sends angels, how could Jesus SEND an angel?  The answer:  He must be God.

Hebrews 1:14 Are they not all ministering spirits, sent forth to minister for them who shall be heirs of salvation?

Revelation 22:6 And he said unto me, These sayings are faithful and true: and the Lord God of the holy prophets sent his angel to shew unto his servants the things which must shortly be done.

3. How could Jesus be BOTH the root and the offspring of David?  The answer:  He must be both God and man, the Maker of David as God and the descendant of David as man.

John 1:14 And the Word was made flesh, and dwelt among us, (and we beheld his glory, the glory as of the only begotten of the Father,) full of grace and truth.