By Dr. Ken Broda-Bahm:
The "swearing in" that precedes testimony is a ritual steeped in religious tradition, though it is routine these days for the oath to simply involve a solemn promise to tell the truth, without any specific religious trappings. But the form of the oath is still often within the judge's discretion, and in some courts, that still means a hand on a Bible. Or for one defendant in a recent trial, it means a hand close to, but not quite touching that Bible. As reported in the New Jersey Law Journal, the near-touch occurred when a defendant of Indian descent, Dr. Abez Husain, apparently felt that touching a holy book with his left hand would be a sign of disrespect. For members of the jury who noticed the gesture, however, it carried a different meaning altogether, bringing the doctor's credibility into question. The case ended in a verdict for the plaintiff, but is now the subject of an appeal.
Of course, that is not a typical situation. But the mechanics, as well as the broader meaning of the oath, should not be overlooked. Whether its administration involves a religious text your witness does not recognize, or is phrased so as to include a "So help me God" that troubles your witness, it is best to work that out in advance. Some muslims, for example, are understandably reluctant to swear on a Bible, but even without the Bible, some draw from the Hadith that they must "Make oaths only on Allah almighty," meaning that they could not swear without a Koran. Whether the courts need to provide a Koran has been the subject of litigation. For atheists and members of nonmajority faiths, including some Christian groups like Quakers (who reject oaths of all kinds), you obviously want to respect the witnesses' conscience. But you also don't want to begin testimony with a moment in court that says to the jury, "I don't respect your religious traditions."