What is the word of reconciliation that God committed to believers?
The word of reconciliation is the message that God was in Christ, reconciling the world to Himself and not imputing trespasses, with the cross work already fully accomplishing reconciliation and forgiveness. Believers are entrusted to tell the lost that everything has been done on their behalf so they can be reconciled to God.
Les explains that God has given believers the ministry of reconciliation, and He has committed to them the word of reconciliation. That word is the good news that God was in Christ, reconciling the world unto Himself, not imputing their trespasses unto them. The work of the cross has already made reconciliation and forgiveness possible for lost mankind. So believers are to tell neighbors, friends, and loved ones that everything has been done on their behalf, that they can close the gap and need not face eternity separated from a holy God. As Les notes, "Jesus paid it all," so reconciliation is not something we add to by our own doing.
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.