Why does the world need to be reconciled to God?
The world is alienated from God, set aside from Him, at odds with Him, and described as enemies of God. Reconciliation brings alienated parties back into fellowship. God in Christ provided the means at the cross, reconciling the whole world and not imputing their trespasses, so people can be restored to fellowship with Him.
Les teaches that reconciliation means taking two parties that have been alienated and are at odds with one another and bringing them back into fellowship. The world is set aside from God, at odds with Him, and even enemies of God, so it needs to be reconciled. Les explains that God has done everything possible to reconcile them to Himself: God was in Christ reconciling not a few but the world, not imputing their trespasses. The work of the cross was the reconciling of the whole world. He notes Hebrews says Christ tasted death for every man, not just for a few believers, but for the whole human race. Believers are therefore ambassadors, carrying out God's bidding while in foreign territory.