dear mP...
the point of mark 2:6-7 is that the jews knew only God could forgive sins. their argument wasn't about the fact that Jesus hadn't died and been resurrected yet to forgive sins.
Jesus had the authority to forgive sins because He WAS God in the flesh not because He died and was resurrected.
In Christ (after His death and resurrection) there is no distinction between jew and gentile because at His death, for the jew, His shed blood was the final sacrifice for the covering over of sins (any one of the 613 that weren't observed to the letter) to gain the forgiveness of God. For gentiles (without the 613 laws) His shed blood covered over all sins that were committed against man and God. (without the shedding of blood there is no remission of sin hebrews 9:22)
whether jew or gentile, sins are not forgiven until they are covered over. that is why in the jewish system you brought a sacrifice to God for forgiveness. psalm 32:1-2
Jesus, by forgiving the sins of both the jews and the gentiles who believed in Him fulfilled God's side of the law(without doing away with one jot or tittle of the jewish law). That is why I quoted mark 2:6-7 "only God can forgive sins"...that is how Jesus fulfilled or put into action the law. In a court of law it is one against another but the law isn't fulfilled or enacted until the judge judges and calls down the sentence.
love michelle