Ever met someone who was not at all what you expected? Maybe it was the mutual friend you've heard stories about for years, or the professor whose reputation preceded him. Maybe it was the first date who looked and sounded nothing like her online profile. 

That sense of confusion we feel when someone isn't who we thought they'd be is the same confusion a lot of Jews felt when Jesus showed up saying He was the Messiah. Everyone knew about the Messiah. They'd heard the stories and waited hundreds of years for his arrival. And Jesus was not what they expected. 

Matthew, one of Jesus' followers, wrote the book of Matthew to document what had happened during Jesus' ministry and to help Jews understand how Jesus' life, death, and resurrection fulfilled every prediction about the Messiah they'd ever heard.