So the group of men had to think of an alternative to get to Jesus. the alternative was to cut a hole through Jesus's roof and lower there friend down from there.
There were some Pharisees and teachers of religious law in the room who said to themselves, "why would Jesus say such thing, only God can forgive sins?!" Jesus heard them thinking and questioned them saying...
"Why do you question this? is it easier to say to this man your sins are forgiven or stand up pick up your mat and walk?"
Jesus continued to talk about why he is allowed to forgive sins