Psalm 110
1 The Lord says to my Lord:
“Sit at my right hand,
until I make your enemies your footstool.”
2 The Lord sends forth from Zion
your mighty scepter.
Rule in the midst of your enemies!
3 Your people will offer themselves freely
on the day of your power,
in holy garments;
from the womb of the morning,
the dew of your youth will be yours.
4 The Lord has sworn
and will not change his mind,
“You are a priest forever
after the order of Melchizedek.”
5 The Lord is at your right hand;
he will shatter kings on the day of his wrath.
6 He will execute judgment among the nations,
filling them with corpses;
he will shatter chiefs
over the wide earth.
7 He will drink from the brook by the way;
therefore he will lift up his head.
This passage is heavily preached on, so you have undoubtedly heard it many times, but hear it again, because as I've learned in college, repetition really does help things stick.
This passage looks like God is saying that he is not ruling over His kingdom yet, but that is absurd, God has always been ruling over his kingdom. But there are still enemies who have not been defeated yet, not because they will not be defeated, because they are a fighting a war that they simply cannot win, death itself has been defeated, so how could God loose? They are not defeated yet though, simply because God has not ended it yet. There is still murdering, there is still theiving, there is still lying. But not because God has lost, God is waiting mercifully for more of his children to come home. But God is not saying "Sit here until I can figure out how to win." This is a "sit here and wait with me for the rest of my children to come home."
If we look at verse two we can see that this isn't a passive point in the Lord's rule, he says "2 The Lord sends forth from Zion your mighty scepter. Rule in the midst of your enemies!" The Lord still commands Christ to rule, this is not a resting point for the Lord's ruling, this is active fighting to win more for the Kingdom of God, this is an active time in the Kingdom of God. God is not lazy, God does not simply wait. I remember a song from when I was younger, it said "my God is an awesome God He reigns." And that He does, He reigns! And if we jump to verses five and six we see again that Christ will not be sitting there awaiting a kingdom to be given to Him, He will "shatter kings," He will be active in the claiming and clearing of His kingdom! And this isn't a passive move, this is a deadly move, "He will execute judgment among the nations, filling them with corpses;" He will end those who are His enemies, they do not get to "pass go and collect $200." It is a final judgment where there will be punishment for those who have not been washed ran by the blood of Christ. And in verse seven we see the completion of these events, Christ "will drink from the brook by the way." He will refresh Himself and continue on His mission, and because He will continue, He will "lift up his head," He will be victorious.
And God even shows us that He is making the correct choice, look at verse three, "your people will offer themselves up freely on the day of your power." And He further clarifies that this is, indeed, the elect! Because He says that they will be in holy garmants and the only way you can get a holy garmant is if Christ has washed you clean and clothed you in said holy garmants. And this is, to me, seems like one of the things God has said to give us a glimpse into His plan, the reason why He doesn't just snap His finger and save everyone, He wants them to freely offer themselves up. But the reason I say this is only a glimpse, is because we cannot freely offer ourselves up unless God has put that desire into our own hearts. This is why I say God works in mysterious ways, it's hard if not impossible, to explain why God works like this!
This passage has so many parts to it, so we're going to take a huge change here and talk about verse four, "4 The Lord has sworn and will not change his mind, “You are a priest forever after the order of Melchizedek.”" Christ is a priest like Melchizedek, that is too say, He will be a priest AND a king simultaneously. This is important because Christ will be an eternal King and if He is a King and a priest simultaneously, then He will also be our priest for eternity. Christ will never resign from priesthood, Christ will never be kicked out of the priesthood, He is the only perfect and eternal priest. Christ is our final priest, Christ is our perfect priest. And the Lord has sworn to this.