2 Cor 4 teaches that it is by God's mercy and grace that we are able to continue serving as ministers and stewards of the Lord's work and not lose heart. Paul says that by sharing openly and sincerely the truth of the light of our faith, others will be sure that we can be trusted. But, the minds of unbelievers are blinded, even if there is nothing hidden about our message. Though God shines in our hearts to let others know his glory, our hearts are frail and weak so that there can be no confusion that the glory is from God.... that "the excellence of the power working in us may undeniably appear to be of God" . Paul says that "outwardly we are wasting away, but inwardly we are being renewed day by day". There is hope in knowing that one day all the stress and heartache of this world will end and we will enjoy rest and rewards in Christ. Therefore, Paul says to live above the pain, knowing our daily troubles and trials are "getting us ready for an eternal glory". So, keep our minds focused not on what is seen, but on this unseen future hope, which is eternal.