Colossians 1:22 begins with “but now” (νυνὶ δὲ). These are two very important words in the Greek, indicating an important contrast. The contrast is between time when we were enemies of God and the present time when we have experienced reconciliation with God. Reconciliation means the relationship is fixed, walls that existed between the two parties are torn down, and that they can now go about the business of building that relationship.
God has reconciled us through the death of Jesus. The basic idea behind reconciliation (καταλλαγή, καταλλάσσω) is the restoration of friendship between two estranged parties. This assumes an offense has separated two parties (political, social, familial, or moral, TLNT 2:263). In non-biblical Greek the word is virtually never used in religious sense primarily because the relationship between the gods and men is not personal. For most of the Greco-Roman world, worship appeased the gods, so a form of ἱλαστήριον (propitiation) would be used.
Josephus reflects the same usage of reconciliation. He uses the related term διαλλάσσομαι for a political agreement between Archelaus and Alexander (the son of Aristobulus) and Herod the Great. After a political arrangement is made, including due honors and gifts, the estranged parties entered into a formal friendship and they “spent their time feasting and agreeable entertainments” (War 1.513, 514). In this example, Herod is in a far superior political position, but he honors Archelaus with great gifts in order to preserve the dignity of all parties.
Unlike secular Greek, Josephus uses καταλλάσσω in a religious sense. In the context of the story of the twelve spies, Moses sought to reconcile God and the people (Ant. 3:315, using the noun.) Similarly, when Saul offended God by sparing the Amalekites (Ant. 6:143), Samuel prays that God “be reconciled” to Saul (using a passive infinitive).
Returning to the earlier analogy of estrangement, the opposite of an estranged relationship is an reconciliation. Rather than a divorce, the married couple overcomes their differences and has decided to remain married, they have reconciled their differences. God saw that we would not turn to him, so he had to provide the method of reconciliation himself. Because the cause of the estrangement was our sin, and the fact that we could not pay for it ourselves.
God therefore provided a way for the debt of sin to be paid. He sent his own son to be killed as an atoning sacrifice so the problem of sin could be permanently solved, once for all.
Paul therefore describes a new state of being for the one who is in Christ. If this is the case and those who were once enemies have now been reconciled through the Cross, what are some implications for how we live out this in Christ life? Paul answers this in the second half of Colossians.