According to Shia theologians, infallibility is considered a rational necessary precondition for spiritual and religious guidance. They argue that since God has commanded absolute obedience from these figures they must only order that which is right. The state of infallibility is based on the Shia interpretation of the verse of purification. Thus, they are the most pure ones, the only immaculate ones preserved from, and immune to, all uncleanness. It does not mean that supernatural powers prevent them from committing a sin, but due to the fact that they have absolute belief in God, they refrain from doing anything that is a sin.