Why did Jesus have the authority to forgive sins, why did the scribes take it as a blasphemy, and was this authority also given to men in general?

In Mark 2:5-12 Jesus surprises the scribes by forgiving the sins of (and miraculously healing) a paralytic. The scribes took it as a blasphemy, as they believed that forgiveness of sins was a prerogative pertaining to God exclusively: 5 A…