What did the Apostle John mean, when he wrote that Christ, the child, "was to rule all nations with a rod of iron" in Revelation 12:5?
We are given an image of the kingdom, the universal church, coming into being after Jesus was resurrected and went back up to the Father. Reading a little further down, a more detailed account is given.
"Then I heard a loud voice in heaven, saying, "Now the salvation, and the power, and the kingdom of our God and the authority of His Christ have come, for the accuser of our brethren has been thrown down, he who accuses them before our God day and night. "And they overcame him because of the blood of the Lamb and because of the word of their testimony, and they did not love their life even when faced with death" (Revelation 12:10-11).
"... and from Jesus Christ, the faithful witness, the firstborn of the dead, and the ruler of the kings of the earth. To Him who loves us and released us from our sins by His blood -- and He has made us to be a kingdom, priests to His God and Father -- to Him be the glory and the dominion forever and ever. Amen" (Revelation 1:5-6; refer also to Revelation 2:26-27).
God has given Jesus rule, dominion and authority over heaven and earth. "And Jesus came up and spoke to them, saying, "All authority has been given to Me in heaven and on earth" (Matthew 28:18). The rod of iron represents Jesus' rule. It is a scepter of Jesus' authority.
This was in fulfillment of prophecy:
"The people who walk in darkness will see a great light; those who live in a dark land, the light will shine on them. You shall multiply the nation, You shall increase their gladness; they will be glad in Your presence as with the gladness of harvest, as men rejoice when they divide the spoil. For You shall break the yoke of their burden and the staff on their shoulders, the rod of their oppressor, as at the battle of Midian. For every boot of the booted warrior in the battle tumult, and cloak rolled in blood, will be for burning, fuel for the fire. For a child will be born to us, a son will be given to us; and the government will rest on His shoulders; and His name will be called Wonderful Counselor, Mighty God, Eternal Father, Prince of Peace. There will be no end to the increase of His government or of peace, on the throne of David and over his kingdom, to establish it and to uphold it with justice and righteousness from then on and forevermore. The zeal of the LORD of hosts will accomplish this" (Isaiah 9:2-7)
Jesus rules with a rod of iron, meaning that He has complete control over his subjects (Romans 13:1). A rod of iron will break and destroy those who are in rebellion before Jesus. "'You shall break them with a rod of iron, You shall shatter them like earthenware.' Now therefore, O kings, show discernment; Take warning, O judges of the earth. Worship the LORD with reverence and rejoice with trembling. Do homage to the Son, that He not become angry, and you perish in the way, for His wrath may soon be kindled. How blessed are all who take refuge in Him!" (Psalms 2:9-12).
"The LORD says to my Lord: "Sit at My right hand until I make Your enemies a footstool for Your feet." The LORD will stretch forth Your strong scepter from Zion, saying, "Rule in the midst of Your enemies." ... The Lord is at Your right hand; He will shatter kings in the day of His wrath. He will judge among the nations, He will fill them with corpses, He will shatter the chief men over a broad country. He will drink from the brook by the wayside; therefore He will lift up His head" (Psalm 110:1-2, 5-7).
No one will be able to overcome Jesus as king. His rule over the nations is absolute and complete. The outcome of those who oppose Jesus as their king is declared before the battle starts.
"And I saw heaven opened, and behold, a white horse, and He who sat on it is called Faithful and True, and in righteousness He judges and wages war. His eyes are a flame of fire, and on His head are many diadems; and He has a name written on Him which no one knows except Himself. He is clothed with a robe dipped in blood, and His name is called The Word of God. And the armies which are in heaven, clothed in fine linen, white and clean, were following Him on white horses. From His mouth comes a sharp sword, so that with it He may strike down the nations, and He will rule them with a rod of iron; and He treads the wine press of the fierce wrath of God, the Almighty. And on His robe and on His thigh He has a name written, "KING OF KINGS, AND LORD OF LORDS." Then I saw an angel standing in the sun, and he cried out with a loud voice, saying to all the birds which fly in midheaven, "Come, assemble for the great supper of God, so that you may eat the flesh of kings and the flesh of commanders and the flesh of mighty men and the flesh of horses and of those who sit on them and the flesh of all men, both free men and slaves, and small and great." (Revelation 19:11-18).
The rod of iron shows judgment, rule and power over ones subjects. For Christians it stirs hope and trust in our King, but for those who oppose the Lord, it is a terrible thing to fall into the hands of the living God.
Thanks for your response.