Jesus was the subject of these questions. It may seem strange for me to write this, but both questions are valid. Each question should be asked by anyone in the presence of someone claiming jurisdiction which God alone possesses. This is a very serious issue in the Bible, and it should be to each of us.
Under Old Testament law a person who claimed God spoke through him (prophet) faced the death penalty if his claim was found to be false. Blasphemy, of the type referenced in this text, takes the issue one step further: instead of speaking for God, a man speaks as God.
Under Bible law this type of speech carries a multifaceted condemnation. It is grossly disrespectful to God by implying that God is equal to a man. It also displays a callous use of God’s name for personal gain or power. Furthermore, the offender is placing himself between God and the hearers.
But Jesus was not blaspheming. He was what His words claimed. He is God manifest in the flesh. As such He possesses the power and jurisdiction of God, and He does have the authority to forgive sins. And all forgiven sinners are eternally thankful He has this jurisdiction.