James 5:12
Above all, my brothers and sisters, do not swear—not by heaven or by earth or by anything else. All you need to say is a simple 'Yes' or 'No.' Otherwise you will be condemned — the prohibition against swearing (omnymi) extends beyond perjury to needless oath-swearing itself, which suggests a lack of trustworthiness in one's word. The principle that a simple affirmation ('Yes,' nai) or negation ('No,' ou) should suffice reflects Jesus's teaching (Matthew 5:33-37) and presumes that a believer's word should be inherently trustworthy. To require oaths suggests one's word alone carries no weight.