most of the unbelief stemmed from unwillingness to believe, because belief in Jesus always costs you something.
for the Pharasees and saducees, they would have had to give up their positions and standing in the community--something they had worked a long time to achieve.
many Jews faced being thrown out of the temple and Jewish society. for others it was wealth that they would have had to given up,or their place in the family, their livelihood (the tax collector),or their status with Rome (Pilot).