Why is both the king of Babylon and Jesus called the morning star?

Answer:

"How you have fallen from heaven, O star of the morning, son of the dawn! You have been cut down to the earth, you who have weakened the nations! But you said in your heart, 'I will ascend to heaven; I will raise my throne above the stars of God, and I will sit on the mount of assembly in the recesses of the north. I will ascend above the heights of the clouds; I will make myself like the Most High.' Nevertheless you will be thrust down to Sheol, to the recesses of the pit" (Isaiah 14:12-15).

"I, Jesus, have sent My angel to testify to you these things for the churches. I am the root and the descendant of David, the bright morning star" (Revelation 22:16).

I assume you are puzzled as to why the king of Babylon (Isaiah 14:4) is called a morning star as well as Jesus.

The morning star (Venus) outshines all the other stars in the early morning hours. As the sun rises, the other stars fade away, but the morning star remains the brightest longest. Powers in government are often described in prophecy as stars. In symbolic language, the sun, moon, and stars represent the governing powers of a nation.

"Behold, the day of the LORD comes, cruel, with both wrath and fierce anger, to lay the land desolate; and He will destroy its sinners from it. For the stars of heaven and their constellations Will not give their light; the sun will be darkened in its going forth, and the moon will not cause its light to shine. I will punish the world for its evil, and the wicked for their iniquity; I will halt the arrogance of the proud, and will lay low the haughtiness of the terrible. I will make a mortal more rare than fine gold, a man more than the golden wedge of Ophir. Therefore I will shake the heavens, and the earth will move out of her place, in the wrath of the LORD of hosts and in the day of His fierce anger" (Isaiah 13:9-13, regarding the destruction of Babylon).

"When I put out your light, I will cover the heavens, and make its stars dark; I will cover the sun with a cloud, and the moon shall not give her light. All the bright lights of the heavens I will make dark over you, and bring darkness upon your land,' says the Lord GOD. I will also trouble the hearts of many peoples, when I bring your destruction among the nations, into the countries which you have not known" (Ezekiel 32:7-9, regarding the destruction of Egypt -- Pharaoh being the light put out by his death).

"Assemble and come, all you nations, and gather together all around. Cause Your mighty ones to go down there, O LORD. Let the nations be wakened, and come up to the Valley of Jehoshaphat; for there I will sit to judge all the surrounding nations. Put in the sickle, for the harvest is ripe. Come, go down; for the winepress is full, the vats overflow - for their wickedness is great." Multitudes, multitudes in the valley of decision! For the day of the LORD is near in the valley of decision. The sun and moon will grow dark, and the stars will diminish their brightness. The LORD also will roar from Zion, and utter His voice from Jerusalem; the heavens and earth will shake; but the LORD will be a shelter for His people, and the strength of the children of Israel" (Joel 3:11-16, concerning God's judgment on the nations surrounding Israel).

"And it shall come to pass in that day," says the Lord GOD, "that I will make the sun go down at noon, and I will darken the earth in broad daylight; I will turn your feasts into mourning, and all your songs into lamentation; I will bring sackcloth on every waist, and baldness on every head; I will make it like mourning for an only son, and its end like a bitter day" (Amos 8:9-10, speaking of the captivity of Israel).

So what God is saying to the king of Babylon is that at this time he is the greatest of the rulers on earth at the moment, the one who outshines all the others. What we learn in Revelation is that this title no longer belongs to some mere mortal man. Jesus is King of kings (Revelation 19:16) and, thus, outshines all the kings of the world.