NOTES for Luk 5:33-39
As we can see, Jesus' attitude toward fasting, like His attitude toward every religious tradition in general, was always very far removed from the religious formalism without which many of His interlocutors could not imagine their lives. Of course, in certain cases fasting is important and necessary, and Jesus by no means opposed the practice itself in principle. The point was something else: every element of religious tradition should serve a person's spiritual formation and growth. Indeed, fasting, at least in Yahwist and Jewish tradition, always presupposed sadness and mourning. It might be family mourning for a deceased relative, public mourning connected with some sorrowful or tragic event of general significance, or, finally, mourning during days of repentance—individual or communal, and sometimes even national, as happened, for example, during the siege of Jerusalem by the Assyrian army in the eighth century BC. In every case, however, fasting had specific content and always possessed a quite definite meaning.
Yet in Gospel times, above all among the Pharisees, fasting had largely become, if not a mere formality, then a purely religious obligation. Everyone knew that a believer should repent of his sins and grieve over them. To regulate this religious practice, the spiritual leaders of the Pharisaic brotherhood established a mandatory fast assigned to two specific days each week, apart from special annual days of mourning. One could, of course, extend the period of abstinence if one wished. Reducing it, however, and declining to keep the prescribed two fast days each week was not exactly forbidden, but was regarded as extremely impious. Such a refusal would almost certainly provoke at least puzzled questions, which is precisely what happened with Jesus' disciples.
Jesus does not even attempt to provide any religious explanation for their refusal to fast. His arguments concern the spiritual life alone: if His disciples have nothing to grieve over now and are not thinking of repentance because He Himself is with them, then fasting has neither meaning nor necessity. When meaning and necessity appear, its time will come as well. There is a time for everything, determined by the logic not of religious regulations but of spiritual life—as is always the case in the Kingdom.