Mark 2:5

2:5 When Jesus saw their faith, he said to the paralytic, “Son, your sins are forgiven.”

Mark 10:43

10:43 But it is not this way among you. Instead whoever wants to be great among you must be your servant,

sn The plural pronoun their makes it clear that Jesus was responding to the faith of the entire group, not just the paralyzed man.

sn The passive voice here is a divine passive (ExSyn 437). It is clear that God does the forgiving.