Original: Christians believe that Jesus, as the Messiah, was anointed by God as savior of humanity, and hold that Jesus' coming was the fulfillment of messianic prophecies of the Old Testament.
Simplified: Christians believe that, as the Messiah, Jesus was anointed by God as ruler and savior of all people. Christians also believe that Jesus' coming was the fulfillment of messianic prophecies of the Old Testament.