An oath is an appeal to something held sacred as support for the truthfulness or sincerity of a statement or vow. It is held by many ethicists that swearing, whatever the circumstances and conditions, is not desirable but an evil necessity of the present age-a really Christian morality would require only a simple “yes, yes” and “no, no” (Matt. 5:33-37). Reformers and certain Protestant communities have held that only when oaths issue from the lower egotistical affections and impulses of human nature are they sinful. If they are pronounced for the sake of high ethical interests, then they are valid. These would interpret Matthew 5:33-37 as a prohibition against the frivolous and promiscuous oaths practiced in the everyday life of the Jews in the time of Christ (see Exod. 20:7; 1 Chron. 12:19; Matt. 23:16-22). The canon laws of the Roman Catholic Church and the Anglican Church have taken their cue from Jeremiah 4:2 which states that an oath should be given in truth, in judgment, and in righteousness. All these moral theologians would deem an oath before God as binding under grave punishment. Throughout the history of the church there have been those who have interpreted Matthew 5:33-37 as totally forbidding all oaths-Waldensians, Quakers, Jehovah's Witnesses, etc. Some governments have acknowledged the rights of these groups to refuse to take oaths.
W. Lockhart, On Oaths (1882); C. Ford, On Oaths (1903); H. Silving, “The Oath,” Yale Law Journal 68 (June/July 1959), pp. 1329-90, 1527-77.