Desecration is a type of behavior that disrespects the sacredness or holiness of something. Words and actions that are offensive to a religion could be considered acts of desecration.
Swearing in church is a type of desecration. Destroying a tombstone is a type of desecration. Depending on the religion, taking God's name in vain could be considered desecration. This word means something close to blasphemy or sacrilege. Sometimes, desecration is used in non-religious contexts, when an idea people care about is treated disrespectfully.