"It is not to angels that he has subjected the world to come, about which we are speaking." NIV translation
Even though Jesus came as a man (lower than the angels), He has still been given authority over all of creation. He came as the lamb for our salvation but He is coming back as a lion to establish His kingdom.
"But there is a place where someone has testified: 'What is man that you are mindful of him, the son of man that you care for him? You made him a little lower than the angels; you crowned him with glory and honor and put everything under his feet.'" NIV translation
We are reminded of the words of King David from Psalm 8. Here, David was talking about the fact that the Creator of all things placed man in charge of His creation on the earth. He could have put angels in charge but He did not. Jesus came as the perfect man and all of the earth responded to His instructions as a demonstration of this authority.
"In putting everything under him, God left nothing that is not subject to him. Yet at present we do not see everything subject to him. But we see Jesus, who was made a little lower than the angels, now crowned with glory and honor because he suffered death, so that by the grace of God he might taste death for everyone." NIV translation
Even though we look around us and see the rebellion of men against God and His Son, Jesus is still in control of all things. We see that God made Him lower than the angels when He came in the form of a baby. This baby grew up and is now crowned with glory because of His resurrection where even death was made subject to Him.
"In bringing many sons to glory, it was fitting that God, for whom and through whom everything exists, should make the author of their salvation perfect through suffering." NIV translation
How was Jesus made perfect through suffering? He was obedient to the Father even to the point of death and so was the perfect sacrifice. This Sacrifice was sufficient to repair the broken relationship between God and men.