Swearing in

Traditionally an oath (from Anglo-Saxon , also called plight) is either a statement of fact or a promise with wording relating to something considered sacred as a sign of verity. A common legal substitute for those who conscientiously object to making sacred oaths is to give an affirmation instead. Nowadays, even when there's no notion of sanctity involved, certain promises said out loud in ceremonial or juridical purpose are referred to as oaths. To is a verb used to describe the taking of an oath, to making a solemn vow.

Usually oaths have referred to a deity significant in the cultural sphere in question. The reciter's personal views upon the divinity of the aspects considered sacred in a predictated text of an oath may or may not be taken in to account. There might not be alternative personal proclamations with no mention of the sacred dogma in question, such as affirmations, to be made. This might mean an impasse to those with unwillingness to edify the dogma they see as untrue and those who decline to refer to sacred matters on the subject at hand.

The essence of a divine oath is an invocation of divine agency to be a guarantor of the oath taker's own honesty and integrity in the matter under question. By implication, this invokes divine displeasure if the oath taker fails in their sworn duties. It therefore implies greater care than usual in the act of the performance of one's duty, such as in testimony to the facts of the matter in a court of law.

A person taking an oath indicates this in a number of ways. The most usual is the explicit "I swear," but any statement or promise that includes "with * as my witness" or "so help me *," with '*' being something or someone the oath-taker holds sacred, is an oath. Many people take an oath by holding in their hand or placing over their head a book of scripture or a sacred object, thus indicating the sacred witness through their action: such an oath is called corporal. However, the chief purpose of such an act is for ceremony or solemnity, and the act does not of itself make an oath.

Making vows and taking oaths became a symbolic concept in law practice that developed over time in different cultures.

...
Wikipedia