Remember Jesus, to whom all things are being put into subjection

You have made him for a little while lower than the angels; you have crowned him with glory and honor, putting everything in subjection under his feet. Now in putting everything in subjection to him, he left nothing outside his control. At present, we do not yet see everything in subjection to him. Hebrews 2:7-8, quoting Psalm 8:5-6 

Now, this is a very similar thought to Jesus being the King even when it doesn't look like it. There's still more to be said, though.

We have here the tense. We see past tense here, although it is clear the event is still to come. This is called prophetic perfect. When God says He's going to do something, it's as good as done. There's no promise He makes that won't be fulflilled. God's yes is never no.

If we are faithless, he remains faithful, for he cannot deny himself. 2 Timothy 2:13 

For God to break a promise, He would have to betray His own character, which He doesn't do, because He doesn't like and He doesn't change. Therefore, when God says He will, He never won't.

So it's coming. But when? We are desperate for Him and it seems to take so long sometimes -

But do not overlook this one fact, beloved, that with the Lord one day is a thousand years, and a thousand years as one day. The Lord is not slow to fulfill his promise as some count slowness, but is patient toward you  2 Peter 3:8-9a 

Everything will be subject to Jesus. Everyone will give Him an account of their lives. God is not slow; He simply operates on another plane of time we don't yet understand. Eternity.

I would also like to point out another thing about Jesus. Many people question Christ's authority as God because He was killed. To that, He says:

You would have no authority over me at all unless it had been given to you from above. John 19:11a

and

For this reason the Father loves me, because I lay down my life that I may take it up again. No one takes it from me, but I lay it down of my own accord. I have authority to lay it down, and I have authority to take it up again. John 10:17-18 

Paul writes of this laying down here -

Have this mind among yourselves, which is yours in Christ Jesus, who, though he was in the form of God, did not count equality with God a thing to be grasped, but emptied himself, by taking the form of a servant, being born in the likeness of men. And being found in human form, he humbled himself by becoming obedient to the point of death, even death on a cros. Therefore God has highly exalted him and bestowed on him the name that is above every name, so that at the name of Jesus every knee should bow, in heaven and on earth and under the earth, and every tongue confess that Jesus Christ is Lord, to the glory of God the Father. Philippians 2:5-11

If all things were subject to Jesus, even as He died, how much more are all things being given to Him now that He lives over death?