Many times in the Bible Jesus referred to himself as the Son of Man. In context it seems as if sometimes he is referring to himself as the fulfillment of prophecy, the Messiah and other times as if he were the sole representative of mankind, the lamb. Please share your thoughts.
Answer
In the Old Testament the phrase "son of man" is used in two different ways. Sometimes it is used to mean "mankind" as a whole, as in Psalm 144:3, which says "LORD, what is man, that thou takest knowledge of him! or the son of man, that thou makest account of him!" At other times it appears to be a prophetic title, as it is used frequently in Ezekiel.
Although Jesus could have used it to indicate his humanity, in most cases he uses the phrase as a title, like Ezekiel. Ezekiel was the prophet of the new Temple and the restoration of God's people in the Messianic time. By using this title he was probably identifying himself as the Messiah, the restorer of God's people to a right relationship with God.