The Debt We Owe is the Gospel of Grace

I'm beginning to daily wade my way through Piper's sermon series on Romans. The following quote is the nuts and bolts of today's message which exhorts us to share the gospel of grace not just with unbelievers, but within the body of Christ.

Grace came to us absolutely free and unconditional from God when he called us to himself and loved us as his own. This grace makes us debtors to everyone who, like us, needs grace, because not to share the grace we received would imply that we qualified for it and they don't; and that would nullify grace. And what we share is the gospel of this great free grace. This is how we pay our debt to others: freely we received, freely we give.