Jesus told them it was inappropriate for his disciples to show sorrow by fasting while he was with them, and that requiring people to perform rituals like fasting was inconsistent with the new way of life he was bringing.

Mark 2:18-22

18 The disciples of John the Baptizer and some men who belonged to the Pharisee sect used to abstain from food to show that they wanted to please God. One day, some people came to Jesus and asked him critically, “The disciples of John and the Pharisees ◄fast/abstain from food► from time to time, but your disciples do not. We think they should abstain from food also. What do you say about that [RHQ]?” 19 Jesus wanted them to understand that it was not appropriate for his disciples to show sorrow by abstaining from food while he was still with them. So he said to them, “When a man is marrying a woman, his friends will certainly not abstain from food while he is still with them, will they [RHQ]? No. During the time that he is with them, they will not abstain from food because they are happy together. 20 But some day, he will be taken away {his enemies will take him away} from them. Then, in those days, they will abstain from food, because they will be sad.”

21 Jesus wanted to show that those who desire to live in accordance with his new message should not try to continue to obey the old religious traditions like fasting. So he also said to them, “People do not sew a patch of unshrunken cloth on an old garment in order to mend a hole. If they did that, when they washed the garment, the patch would shrink and the new piece of cloth would tear off more of the old cloth. As a result, the hole would become bigger! 22 Similarly, people do not put newly squeezed grape juice into old skin bags to store it. If they did that, that juice will burst the skin bags because they would not stretch when the wine ferments and expands. As a result both the wine and the skin bags would be ruined! On the contrary, people must put new wine into new skin bags!” [MET]