This article poses a perennial question of what miracles are and of whether miracles can really happen from the perspectives of the Old Testament and its authors. It aims to clarify the definition of miracles that the books of the Old Testament (to be abbreviated as OT hereafter) describe, to examine its differences from the modern definition of miracles by comparison, and to suggest how to read and understand the miracle stories of the OT.
 Our inquiry about miracles proceeded in three steps. First, I examined the meanings and lexical usages of various terms for miracles in the OT to figure out the definition of miracles that the authors of the OT might have kept in their mind. The terms for miracles are ’ôt, môpët, Gübûrâ, pele, niplä’ôt, Güdôlöt, and the like. Interestingly none of these correspond with the modern terms of miracle.
 Secondly, I analyzed the text of Exodus 14 which narrates the Sea Event, one of the representative miracle stories in the Hebrew Bible. Referring to the achievements of historical critical studies on this text, I distinguished various motives and traditions inherent in the text, and attempted to grasp its core messages, revealed through their polyphonic voices. By and large two themes are found in Exodus 14. One is about God’s sovereignty. God is described as the one who freely exploits either the power of nature or supernatural force and smashes Pharaoh’s chariots and his whole army. The other is about God’s protection for his people and about proper response to it. Since the same God is the one who protects and supports the Israelites, they should fear and trust in him. These themes are repeated in the phrases which recount the Sea Event. By the way, scholars, who tend to acknowledge the historicity of the core substance of the story, accept the naturalistic explanation of the event from the text, while disregarding the supernatural descriptions of it as either a secondary source or a later embellishment. As a result, such attempts lead to neglecting some integral elements in the text. Their efforts to make believe the story, by eliminating supernatural and mythic components of the text, lead to miss the important themes that Exodus 14 conveys.
 Third, it would be necessary to examine the ways in which the ancient Israelites perceived the world, history and nature in order to understand the miracle stories in the OT. They had not questioned the possibility of miracles. Instead, they took it for granted that God can intervene in nature and history at any time he needs since he is the Lord who governs his created world and the world keeps its integrity only with God’s support.
 Ancient Israelites’ understanding of miracles is closely connected with their belief that God is always working in the history of salvation. Biblical miracle stories were written down and transmitted for the purpose of strengthening and edifying their faith in God. In this sense, the story of the Sea Event in Exodus 14 had a great influence on the growth of their faith. Therefore, I suggest that a proper way to read the miracle stories in the OT is not to pose a question of whether the miracles that the text presents would be possible or not, but to ask what theological, heuristic, and ethical messages are conveyed through them.