"He is the image of the invisible God, the firstborn over all creation. For by him all things were created: things in heaven and on earth, visible and invisible, whether thrones or powers or rulers or authorities; all things were created by him and for him. He is before all things, and in him all things hold together. And he is the head of the body, the church; he is the beginning and the firstborn from among the dead, so that in everything he might have the supremacy. For God was pleased to have all his fullness dwell in him, and through him to reconcile to himself all things, whether things on earth or things in heaven, by making peace through his blood, shed on the cross." (Colossians 1:15–20)
This passage summarizes the whole sweeping scope of God's magnificent purposes for His creation, climaxing in the reconciliation of all things to Himself. What does Paul mean when he says that through Jesus, God will "reconcile to himself all things"? The context here, in conjunction with other passages, identifies the extent of "all things" and defines the meaning of "to reconcile."
Verse 16 says, "For by him all things (τα παντα) were created." Paul goes to great lengths to show that "all things" means absolutely everything (with the exception, of course, of God Himself). In verse 15, he says that Christ is "the firstborn over all creation" (πασης κτισεως). In verse 16 he elaborates on what he means by "all things": "things in heaven and on earth, visible and invisible, whether thrones or powers or rulers or authorities; all things were created by him and for him."
The phrase things in heaven and on earth is itself enough to show that he means everything without exception. (Cf. Jesus' use of the phrase in Matthew 28:18—"All authority in heaven and on earth has been given to me." Is there anything not under His authority?) Paul goes on to say "visible and invisible," which includes everything material and spiritual. He further specifies all kingdoms of every kind: "whether thrones or powers or rulers or authorities." To emphasize, he states the proposition again: "all things (τα παντα) were created by him and for him." Absolutely everything was brought into existence by and for Jesus Christ.
When Paul uses the phrase all things in the rest of the passage, he is referring to the same things. Verse 17 says, "He is before all things (προ παντων), and in him all things (τα παντα) hold together." He was in existence before the created world came into being, and now He holds it all together. Furthermore, He is the head of the church, the beginning and the firstborn from among the dead, "so that in everything (εν πασιν) he might have the supremacy" (v. 18).
Verse 19 says that "God was pleased to have all his fullness (παν το πληρομα—not some or most of it) dwell in him." And verse 20 is the climax of this passage: God was pleased "through him to reconcile to himself all things (τα παντα), whether things on earth or things in heaven, by making peace through his blood, shed on the cross." Paul identifies the "all things" in verse 20 using a phrase very similar to the one in verse 16:
16: by him all things were created: things in heaven and on earth
20: to reconcile to himself all things, whether things on earth or things in heaven
It stands to reason that "all things" in verse 16 is parallel to "all things" in verse 20, so the extent in each case must be the same. By Jesus, all things were created; through Jesus, all things will be reconciled.
So this passage seems to say that all created things will be reconciled to God. Since human beings are created things, it suggests that all human beings will be reconciled to God. But what does it mean to be reconciled? Again, the context of this passage, along with information from other passages about reconciliation, will give the meaning. The dictionary definition and the etymology of the word will also shed light on the meaning.
Verse 20 itself suggests the meaning of the word by the phrase that is set in apposition to it:
 and through him to reconcile to himself all things, whether things on earth or things in heaven, by making peace through his blood, shed on the cross.
The phrase making peace indicates that reconciliation involves peace between the two parties, in this case, God and all things.
The next verse contains two phrases that describe the opposite of reconciliation—the state we were in before we were reconciled:
 Once you were alienated from God and were enemies in your minds because of your evil behavior.
We were "enemies" of God. Our sin ("evil behavior") caused us to be "alienated" from God—estranged from Him, hostile toward Him, on unfriendly terms with Him. So being reconciled to God would change us from enemies of God to friends of God.
The next verse amplifies the meaning of reconciliation:
 But now he has reconciled you by Christ's physical body through death to present you holy in his sight, without blemish and free from accusation.
Jesus' death on the cross enables Him to present us "holy in his sight, without blemish and free from accusation." Because Jesus has paid for our sin, we can be in the presence of God without guilt or stain. So being reconciled also involves getting rid of the sin that stands between us and God; then we can have a free and open friendship with Him.
The word reconcile (αποκαταλλασσω) is also found in Ephesians 2, which adds to the understanding of what the word means and what its opposite is:
Remember that at that time you were separate from Christ, excluded from citizenship in Israel and foreigners to the covenants of the promise, without hope and without God in the world. But now in Christ Jesus you who once were far away have been brought near through the blood of Christ. For he himself is our peace, who has made the two one and has destroyed the barrier, the dividing wall of hostility, by abolishing in his flesh the law with its commandments and regulations. His purpose was to create in himself one new man out of the two, thus making peace, and in this one body to reconcile both of them to God through the cross, by which he put to death their hostility. He came and preached peace to you who were far away and peace to those who were near. For through him we both have access to the Father by one Spirit." Consequently, you are no longer foreigners and aliens, but fellow citizens with God's people and members of God's household.
This passage teaches that in Christ, God is not only reconciling people to Himself, but also reconciling people to one another (in this case, Jews and Gentiles—who constitute all of mankind). The following phrases in the passage describe being reconciled and not being reconciled:
separate from Christ
excluded from citizenship in Israel
foreigners to the covenants of the promise
without hope and without God in the world
far away, hostile
separated by a barrier, the dividing wall of hostility
brought near through the blood of Christ
he himself is our peace
has made the two one
has destroyed the barrier, the dividing wall of hostility
to create in himself one new man out of the two
in this one body to reconcile both of them to God through the cross
put to death their hostility
preached peace to you who were far away and peace to those who were near
we both have access to the Father by one Spirit
no longer foreigners and aliens
fellow citizens with God's people
members of God's household
A prominent theme here is "peace"—Jesus Himself is our peace, He makes peace, He preaches peace. When we are reconciled, the hostility is gone and there is peace between God and mankind and peace among people.
Similar words for reconcile (καταλλασσω) and reconciliation (καταλλαγη) are found in Romans 5:
For if, when we were God's enemies, we were reconciled to him through the death of his Son, how much more, having been reconciled, shall we be saved through his life! Not only is this so, but we also rejoice in God through our Lord Jesus Christ, through whom we have now received reconciliation.
This passage shows that we are reconciled through the death of God's Son and saved through the life of His Son. When we are reconciled to God, we are no longer His enemies, so we can rejoice in Him.
The words καταλλασσω and καταλλαγη are used five times in 2 Corinthians 5. This passage sheds further light on what it means to be reconciled.
Therefore, if anyone is in Christ, he is a new creation; the old has gone, the new has come! All this is from God, who reconciled us to himself through Christ and gave us the ministry of reconciliation: that God was reconciling the world to himself in Christ, not counting men's sins against them. And he has committed to us the message of reconciliation. We are therefore Christ's ambassadors, as though God were making his appeal through us. We implore you on Christ's behalf: Be reconciled to God. God made him who had no sin to be sin for us, so that in him we might become the righteousness of God.
This passage says that God "reconciled us to himself through Christ" and that "God was reconciling the world to himself in Christ." What does that mean? Again, phrases in the passage give the clues:
not counting men's sins against them
so that in him we might become the righteousness of God
As in the other passages, "reconciliation" here means a complete cessation of hostility and a complete restoration of our relationship with God, as we "become the righteousness of God."
The dictionary definition of the word reconcile confirms this understanding of the meaning of the word. Its definition is "to re-establish friendship between" (American Heritage Dictionary); "to win over to friendliness; cause to become amicable" (Random House Dictionary). Thayer's Greek-English Lexicon says that the New Testament uses the word καταλλαγη to refer to the restoration of the favor of God. Similarly, καταλλασσω means "to reconcile those who are at variance, to be restored to the favor of God." The word αποκαταλλασσω means "to reconcile completely," "bring back to a former state of harmony."
Returning to Colossians 1, we see the entire scope of the history of the universe and God's grand plan for it:
In the beginning Jesus created all things (v. 16).
In the present all things hold together in Him (v. 17).
In the end He will reconcile to Himself all things (v. 20).
The passage even says that Christ existed before the created world came into being: "He is before all things" (v. 17).
So Jesus existed before all things, He created all things, He holds together all things, and He will reconcile all things. And what does it mean for God to "reconcile to himself all things"? It is clear that the word reconcile means more than squashing opposition. It means a full restoration of peace and harmony. It is true that the word all in Scripture does not always mean "absolutely all," but in this passage about the supremacy of Christ, I believe that the word παν in its different forms (πασης / παντα / παντων / πασιν / παν) does mean "all without exception" in each of the eight instances where it is used in the passage. The "all things" of verse 20 is as extensive as the "all things" of verse 16. So just as God created everything and everybody through Christ, so He will reconcile everything and everybody through Christ (not everything except most of humanity!). The universe will be completely restored to its original perfection and peace. No one will be at enmity with God or with one another. He will completely fulfill "the mystery of his will according to his good pleasure"—"to bring all things in heaven and on earth together under one head, even Christ" (Ephesians 1:10). Going from the depths of mankind's depravity to the total reconciliation of everyone to God and to each other will be more glorious than if we had never fallen in the first place. The restoration of every single relationship to perfect harmony through the work of reconciliation on the cross will be the most spectacular demonstration imaginable of the grace and justice and wisdom and power and love of God.