 William Hasker, perhaps the most prominent advocate of open theism, addresses this problem explicitly, and suggests a three-fold response. First, he points out that the main function of prophecy is not to foretell the future, but to reveal God’s will (Hasker 1989, 194). Many prophecies, in fact, have a conditional character, such as “If a nation does not do such and such, then it will be destroyed” (see Jeremiah 18:7–10, for example). Second, many prophetic predictions are based upon existing trends and tendencies, which provide God with enough evidence to foresee the future (Hasker 1989, 195). (Hasker places Jesus’ prediction about Peter in this category, by the way.) Finally, some prophecies simply reveal what God has already decided to bring about in the future (Hasker 1989, 195). Since God’s own actions in the future are up to God, it is possible for God to know about them even though they are contingent, so it is possible for prophecies to reveal them.