Presumption most commonly refers to an attitude or behavior that is boldly arrogant or offensive; sheer effrontery. Insult. For example, a judge or governmental official will rightly be offended at an individual's disrespectful presumption in speaking in a casual manner, or acting as if he or she is equal to or has more authority than the judge or official. Contempt of court. Condescending attitude.
Presumption is also an act of presuming or accepting something as true without proof; also called assuming. A presumption is also an assumption. Prejudice.
Political anarchists presume that there is no need for governments or political authority, and presume to set aside the need for laws, often in contempt for the government. See Individualism and Conspiracy theory. Compare Civil disobedience.
In Christianity presumption is a sin opposed to the Theological virtue of hope. The opposite sin is despair. Presumption is committed by anyone who either trusts too much in their own strength or who, in order to attain salvation, expects God to do something that He would not will to do (Sloth and Quietism). Compare Exodus 14:14-15. Persons who expect to attain salvation only by their own efforts (Pelagianism) or who think they will attain salvation on account of the merits of Christ alone without applying His merits or seeking them and exercising them for the benefit of both themselves and others, sin by presumption. James 2:14-26; Luke 12:41-48; 19:12-26; Matthew 25.