As God's fellow worker, Paul urges the Corinthians not to receive the grace of God in vain. He quotes a promise of God about the acceptable time and day of salvation and affirms that this time is now. They give no cause for offense in anything, so that the ministry will not be discredited.
In everything they present themselves as servants of God: with great endurance in afflictions, hardships and calamities, under beatings, imprisonments and riots, in labors, sleepless nights and hunger. They do it with purity, knowledge, kindness, the Holy Spirit, genuine love, truthful speech and the power of God. They pass through honor and dishonor, good report and bad. They are treated as impostors, yet are true; as unknown, yet well known; as dying, yet alive; as punished, yet not killed; as grieving, yet always glad; as poor, yet enriching many; as having nothing, yet possessing everything.
Paul says his mouth is open to the Corinthians and his heart is wide. They are not restricted by him, but by their own affections. He asks them, as children, to widen their hearts in return.
He then urges them not to be unequally yoked with unbelievers, and asks what righteousness and wickedness have in common, or light and darkness, Christ and Belial, a believer and an unbeliever, the temple of God and idols. They are the temple of the living God, for God promised to live and walk among his people and be their God. So they must separate from what is unclean; then God will welcome them as a Father, and they will be his sons and daughters.