What is Blasphemy?
Blasphemy is considered as a religious offense, consists of scornful, disrespectful, or insulting words or actions directed against God. In its gravest form, blasphemy is a deliberate, intentional attack on the honor or holiness of God. Blasphemy is generally expressed through speech by imprecations directed against God or commands for God to curse another, but it may also find expression through actions—shaking one's fist toward the heavens or desecrating a sacred object—or even in unexpressed thoughts.
Traditionally blasphemy has been considered among the gravest of sins. Ancient paganism proscribed it; the law of Moses made it an offense punishable by death ("He who blasphemes the name of the Lord shall be put to death"; Leviticus 24:16). Christ spoke of blasphemy against the Holy Spirit as a wrong without pardon either in this world or the next (Matthew 12:24-33).
The Roman law code of Emperor Justinian prescribed capital punishment as the penalty for blasphemy. Though such a penalty is unthinkable today, the gravity of blasphemy as a sin has not lessened. In the language of moral theologians, blasphemy still is a sin which, by its entire nature, is grave or mortal. Unless emotional or mental distress diminishes full awareness of its gravity, it cannot be committed without serious guilt. In Roman Catholic canon law, blasphemy is a crime; its penalty is left to the prudent discretion of a superior (Canon 2323).