‘Therefore seeing we have this ministry, even as we obtained mercy, we do not faint.'
Having such a ministry which results in the unveiling of men and women (2 Corinthians 3:18) so that they can behold the glory of God in the face of Jesus Christ (2 Corinthians 4:6), or in unveiling Jesus Christ so that men can see Him, something which they themselves have also obtained through His mercy, how can they faint? It would be inconceivable.
‘Even as we obtained mercy.' Paul's life is lived in remembrance of the mercy of God, and he assumes others' lives are too. He could never quite get over how God had reached him when he was a renegade and a rebel, working to keep the veil on men's minds and hearts. But God had been merciful and this makes him press on against every obstacle.
‘We do not faint.' The verb has a variety of meanings, ‘do not get discouraged', ‘do not despair', ‘do not cease working', ‘do not get tired', ‘do not have an aversion to it', and so on. They do not let obstacles get in their way or find it distasteful.