Final answer:
Matthew arranged the genealogy in groups of fourteen generations to highlight the lineage of Jesus as the Messiah.
Step-by-step explanation:
Matthew was concerned with arranging the genealogy in groups of fourteen generations because he wanted to highlight significant periods in history. In Jewish tradition, the number fourteen was associated with King David, who was seen as a symbol of the Messiah. By organizing the genealogy into groups of fourteen, Matthew was emphasizing the lineage of Jesus as the long-awaited Messiah.