Read Luke 5:33-39
"And no one pours new wine into old wineskins"
The religious Jews in that time used to fast twice a week, on Mondays and Thursdays from 6.00am to 6.00pm. The whole scope of fasting was to express concretely their desire to get closer to God. Of course, if there was a wedding feast, which could take up to a whole week of joyful celebration, there would be no fasting. The disciples were enjoying a wedding feast with Jesus because the ‘bridegroom’, God Himself, was with them. Because of this they didn’t need to fast - and so some of the Jews saw this as shameful.
Jesus wanted to pour the new wine of the Good News to all His people. But some of His hearers were so caught up in legalism and mere external and rigid religiosity that they weren’t free to believe and open themselves to the ‘new wine’. They were like old and dry wineskins which couldn’t expand when new wine which when fermenting emitted gases, was poured into them. In the same way today, when some people who have been Catholics or Christians all their lives are challenged to life in the Spirit (the new wine) they reject it, preferring to go through the motions of religious and habitual ritual (old wineskins) than really encountering Jesus.
Lord, let me always see that prayer, fasting and good works are expressions of faith and love for You, rather than lifeless and self-righteous end in themselves.