The question about fasting is raised here by the disciples of John the Baptist. Jesus’ first response is that the wedding guests do not fast during the wedding. In other words the time of Jesus is considered as a time of celebration, it is the time of the presence of the Kingdom of God. The second and third responses are about the new cloth and old garment and about new wine in old wine skins. The point here seems to be that both have their place in appropriate settings and must not be mixed up. Fasting does have a place in spirituality, but must not be made an end it itself.
It is possible that even our good actions might take a hold of us and so become ends in themselves. There is only one end: God and all else that we do even if it is good can never be an end. We must use them as means to reach God. This means that if something helps me, I use it, if it hinders me I give it up.