Who was God reconciling to Himself in Christ—a few or the world?

God was in Christ reconciling not a few, but the world. The cross was the reconciling of the whole world, not merely a few believers. Christ tasted death for every man; He died for the whole human race, not just the few who believe.

Les explains that reconciliation means taking two parties that have been alienated and at odds and bringing them back into fellowship. He says the world is set aside from God, at odds with Him, and enemies of God, and God has done everything possible to reconcile them to Himself. In the passage, Les emphasizes that God was in Christ, reconciling not a few, but the world. He notes that God was in Christ on the cross, reconciling the whole world unto Himself, not imputing their trespasses. The work of the cross was the reconciling of the whole world. Hebrews says Christ tasted death for every man, not just the few believers, but the whole human race. As such, believers are ambassadors carrying out God's bidding in foreign territory.

2 Corinthians 5:19

To wit, that God was in Christ, reconciling the world unto himself, not imputing their trespasses unto them; and hath committed unto us the word of reconciliation.

When did God reconcile the whole world to Himself?

God reconciled the whole world to Himself at the cross, when Christ hung on that cross. The work of the cross was the reconciling of the whole world, not a few. God was in Christ, not imputing their trespasses unto them, and committed unto us the word of reconciliation.