The following is from Grace To You:
With that brief question Jesus Christ confronted His followers with the most important issue they would ever face. He had spent much time with them and made some bold claims about His identity and authority. Now the time had come for them either to believe or deny His teachings.
Who do you say Jesus is? Your response to Him will determine not only your values and lifestyle, but your eternal destiny as well.
Consider what the Bible says about Him: http://www.gty.org/resources/articles/A335