For bodily exercise has some value, but godliness has value for all things, having the promise of the life which is now, and of that which is to come.
but godliness is profitable unto all things, having promise of the life that now is, and of that which is to come: Paul’s discussion of training or exercising oneself for godly living is a natural bridge to a comparison with the athletic world from which Paul frequently borrowed metaphors (Romans 9:16; 1 Corinthians 9:24-27; Galatians 2:2; Galatians 5:7; Philippians 2:16; 2 Thessalonians 3:1; Hebrews 12:1-2). Some, however, believe that the comparison is between two forms of asceticism (Lenski, MacKnight, for example): one that is condemned in verses 3-5 and is of no profit, and one that is a useful discipline to perfecting godliness--that is, refusing to allow physical appetites to rule the will. While this view is possible, it seems unlikely, at best. The comparison seems more likely to be between ordinary physical exercise that profits a little temporarily and godliness that profits much eternally. The simplest view is that physical exercise is of small, temporary benefit, but godliness, in contradistinction, is profitable not only for this life but also in eternity. Godliness should be understood as that conduct of life that is measured by and in accord with the standard of the word of God (2 Timothy 3:16). If a Christian trains himself to be closely aligned with God’s word, he will be profited both here (Matthew 5:5; Matthew 6:31-34; Matthew 19:29; 1 Corinthians 3:21-23) and in eternity (Matthew 19:29). Whatever can be gained through bodily (physical) exercise, on the other hand, is only of benefit here on earth and that temporarily.