Despite the fact that many Jews believed in who Jesus was, many others rejected him. In particular, Jesus clashed with the Pharisees because he demanded that they abandon practices that were counterproductive to advancing the kingdom. (Ps. 110:4; Heb. 7:10-22), and a new Covenant (Jer. 31:31).
The precise reason why Jesus says: “you cannot put new wine into old bottles,” is because new wine is so vibrant it expands or grows at a much faster rate than old wineskins. If new wine, still fermenting, is poured into an old skin, the pressure buildup from the fermenting gases will explode the leather bottles ruining both the wine and bottle.