“Why do John’s disciples and the disciples of the Pharisees fast, but your disciples do not fast” (Mark 2:18) – a reasonable question it seems. And once again, Jesus answers a question with a question. In referring to Himself as the bridegroom, we are drawn to the Old Testament allusion of Yahweh as the bridegroom of Israel (Is. 62:5, Hos. 2:19-20). To fast at a wedding, a time of rejoicing and celebration, would be preposterous, unthinkable.
The presence of Jesus with His disciples calls for joy and celebration.
Yet, at the same time, Jesus refers to a time when He would be “taken away from them” (v.20). Are the disciples getting it at this point? Jesus will suffer and die. The path ahead for them is filled with difficulty and trial. The road to Jerusalem is the path to suffering and death – “Follow Me!” Did the 12 understand this at this point – probably not. But this will become much clearer later on in Mark’s gospel (8:31f.) Did the original readers of John’s Mark’s gospel get this – almost surely (hindsight is 20-20).
Now Jesus suddenly utters two parables which at first seem quite unrelated to the question on fasting at hand. An unshrunk patch causes a tear in the old garment (v. 21)? New wine in old 
wineskins causes the old to burst – the skins are destroyed and the wine is lost, spilled all over the floor! “But new wine is for fresh wineskins” (v. 22)! The commentaries are fairly unanimous here. Jesus ushers in a completely new era – the new covenant, the kingdom of God – it just won’t fit into the old paradigms even of John the Baptist (an Old Testament style prophet). Sorry for the cheesy DC Talk reference, but God is doin’ a Nu Thang!
The fact that Levi was just invited into the inner sanctum of this Rabbi’s disciples and that Jesus hangs out and celebrates (parties) with these traitors and welcomes & embraces sinners, makes it quite clear that the religion of the Pharisees is pretty much the farthest thing from the radically altered situation that Jesus initiates on earth. Religion is almost always used by human beings to help us feel good about ourselves. In general, the way this plays out typically in human religion is that the way I accomplish this is by: “Look at me. I’m a good, religious person! I’m in right standing with God here. Not like that guy over there!”
Such a religion couldn’t be further from the Kingdom of God as taught and enacted by Jesus.
“Follow Me…”
what is this