Jesus came so that we would have life, now and for eternity. We are made new creatures in Him, and through Him, leaving the past behind. Even so, we cannot resist the temptation to graft at least part of the old self, to our recreated body.
No one sews a patch of unshrunk cloth to an old garment, Jesus said, for the patch will pull away from the garment. Often, we try to take the hurts and pains of years ago, and attach them to our present self. We even attempt to stitch previous regrets, into this new fabric. But it will not work. Sooner or later, everything will unravel. The tear in our lives will become worse, perhaps even beyond repair.
Jesus adds that it is impossible to put new wine into old, worn out wineskins. If we do, He says, the skins will burst; the wine will run out all over, and the wineskins will be ruined. Our lives are much the same. We cannot fill ourselves with the new life of Christ, without letting Him change us completely.
He must remake us both on the outside, and inside, so that His life, and love, can be preserved within us. It is impossible to live for Him, if we only patch up our wounds. Eventually, the seam will rip apart, unless we are fully restored by His hand.