That I may make it manifest, as I ought to speak (Ephesians 6:20; 2 Corinthians 2:17; 2 Corinthians 4:1-6; 2 Corinthians 5:11, 20-6:10; Romans 12:6; 2 Timothy 2:24-26; 2 Timothy 3:10; Acts 20:18-21, Acts 20:27, Acts 20:33-35).
This clause qualifies the last; the "open door" is to be asked for the apostle, that he may make effective use of it. The mystery has been made manifest by God in the mission of Christ (Colossians 1:27; Colossians 2:15, note; 2 Corinthians 5:19, etc.
); but that manifestation has to be made known to the Gentile world (Ephesians 3:9; 2 Corinthians 2:14; Romans 10:14). To this end he had received a special manifestation of "the mystery of Christ" (2 Corinthians 4:6; 2 Corinthians 5:19; Galatians 1:15, Galatians 1:16; Acts 9:15, Acts 9:16; Acts 22:14, Acts 22:15, Acts 22:21; Acts 26:16-18).
How the apostle conceives that he "ought to speak" appears from the parallel passages (see especially 2 Corinthians 5:1-21.; 6.; and Acts 20:1-38.).