Vincent's Word Studies
God
Emphatic. It was God, as in
2 Corinthians 5:18.
Was - reconciling (ἦν καταλλάσσων)
These words are to be construed together; the participle with the finite verb marking the process of reconciliation. The emphasis is on the fact that God was reconciling, not on the fact that God was in Christ. God was all through and behind the process of reconciliation. The primary reference of the statement is, no doubt, to God's reconciling manifestation in the incarnation and death of Christ; yet, as a fact, it includes much more. God was engaged in reconciling the world from the very beginning, and that in Christ. See on
John 1:4,
John 1:5,
John 1:9,
John 1:10.