Blasphemy has two definitions in Scripture…
Blasphemy 1: Claiming to Forgive Sins:
(Luke 5:18) And, behold, men brought in a bed a man which was taken with a palsy: and they sought means to bring him in, and to lay him before him.
(Luke 5:19) And when they could not find by what way they might bring him in because of the multitude, they went upon the housetop, and let him down through the tiling with his couch into the midst before Jesus.
(Luke 5:20) And when he saw their faith, he said unto him, Man, thy sins are forgiven thee.
(Luke 5:21) And the scribes and the Pharisees began to reason, saying, Who is this which speaketh blasphemies? Who can forgive sins, but God alone? .
What does the Papacy say about this? Can the priest forgive sins?
“Does the Priest truly forgive the sins, or does he only declare that they are remitted?”
“The Priest does really and truly forgive the sins in virtue of the power given to him by Christ.” (Joseph Deharbe, S.J., A Complete Catechism of the Catholic Religion (New York: Schwartz, Kirwin & Fauss, 1924), p. 279)
Blasphemy 2: Claiming to be God:
(John 10:30) I and my Father are one.
(John 10:31) Then the Jews took up stones again to stone him.
(John 10:32) Jesus answered them, Many good works have I shewed you from my Father; for which of those works do ye stone me?
(John 10:33) The Jews answered him, saying, For a good work we stone thee not; but for blasphemy; and because that thou, being a man, makest thyself God.
Does the Papacy claim to be God?
“We [the popes] hold upon this earth the place of God Almighty.” (Pope Leo XIII, Encyclical Letter “The Reunion of Christendom” (dated June 20, 1894) trans. in the Great Encyclical Letters of Pope Leo XIII (New York: Benziger, 1903), p. 304)
“The pope is not only the representative of Jesus Christ, but he is Jesus Christ, Himself, hidden under the veil of flesh.”Catholic National, July 1895)