Some of the future is determined and settled by God (e.g. the incarnation, death, resurrection, Second Coming, future judgments). Other aspects of the future are open and unsettled (e.g. free choices like who will win the Superbowl in 10 years, the eternal destiny of an infant before they receive or reject Christ, what I will eat for lunch in 3 years, if I am even alive, etc.).
So, the determined, predictive prophecies will come to pass due to God's ability (not foreknowledge) to make them come to pass (Is. 46; Messianic prophecies, etc.).
Many other prophecies are conditional and may or may not come to pass depending on the response of the people to God's call to repentance (Jonah; Hezekiah). These prophecies are not predictive, but proclamations to make a choice. Depending on the choice, the consequences will vary.