Without this witness of the death, burial and resurrection of Christ our message is simply not Christian.
We are not just witnesses. Christ’s words were “you shall be My witnesses.” The emphasis is on “My.”
Paul I believe takes this even deeper in 2 Corinthians 5. I agree with John Stott that verse 21 is the key that unlocks Scripture. “He [God] made Him who knew no sin to be sin on our behalf, so that we might become the righteousness of God in Him.”
Put in the context of the whole chapter we are ambassadors for Christ. It’s God making his appeal through us, “we beg you on behalf of Christ, be reconciled to God.”
It comes back to the cross and the resurrection. There God reconciled us to Himself through Christ and gave us the ministry of reconciliation. Ours is the ministry of reconciliation and it is our God given witness. We are ambassadors of reconciliation.
But it goes deeper yet. It is this, “… namely, that God was in Christ reconciling the world to Himself, not counting their sins against them.”
This is the message of reconciliation that God has given to us. Are we prepared to tell the world, every individual that we meet that they are already reconciled to God because God was in Christ on the cross doing just that.
Further, are we prepared to tell every person we meet that God does not count their sins, their trespasses, against them? Are we clear in our witness that since Calvary, God keeps no record of sin.
The reality is that God made Jesus, who knew no sin, to be sin for us. Why? So that in Christ, we might become the righteousness of God.
Ambassadors of such a reconciliation is our calling. God is making His appeal through us to every lost soul.