I’m not well read on the subject of Christian fasting but I found Bonhoeffer’s comments on the practice both concise and convicting {“Ooh, alliteration. I’m persuaded.” -Shive}. As he does throughout The Cost of Discipleship, Bonhoeffer takes Christ’s teaching seriously (see Mat 6:16-18) and thereby rejects any pretense to Christian liberty that would blunt the sharpness of the command.
The chapter begins with an essential premise and a singular purpose for fasting. According to Bonhoeffer “Jesus takes it for granted” that his disciples will fast (i.e ‘When you fast…’), the purpose of the act is “to make the disciples more ready and cheerful to accomplish those things which God would have done.” From there Bonhoeffer goes on to say:
…If there is no element of asceticism in our lives, if we give free rein to the desires of the flesh (taking care of course to keep within the limits of what seems permissible to the world), we shall find it hard to train for the service of Christ. When the flesh is satisfied it is hard to pray with cheerfulness or to devote oneself to a life of service which calls for much self-renunciation.
So the Christian needs to observe a strict exterior discipline. But we are not to imagine that that alone will crush the will of the flesh, or that there is any way of mortifying our old man other than by faith in Jesus. The real difference in the believer who follows Christ and has mortified his will and died after the old man in Christ, is that he is more clearly aware than other men of the rebelliousness and perennial pride of the flesh, he is conscious of his sloth and self-indulgence and knows that his arrogance must be eradicated. Hence there is a need for daily self-discipline . . . only so can the flesh learn the painful lesson that it has no rights of its own. Regular daily prayer is a great help here, and so is daily meditation on the Word of God, and every kind of bodily discipline and asceticism.
The flesh resists this daily humiliation, first by a frontal attack, and later by hiding itself under the words of the spirit (i.e. in the name of “evangelical liberty”). We claim liberty from all legal compulsion, from self-martyrdom and mortification, and play this off against the proper evangelical use of discipline and asceticism; we thus excuse our self-indulgence and irregularity in prayer, in meditation and in our bodily life. . .When all is said and done, the life of faith is nothing if not an unending struggle of the spirit with every available weapon against the flesh. How is it possible to live the life of faith when we grow weary of prayer, when we lose our taste for reading the Bible, and when sleep, food and sensuality deprive us of the joy of communion with God?
Is it possible that we don’t fast simply because we’re not convinced that there’s more joy in God than food?
according to Script 