Jesus is the Messiah because the Bible testifies so (Matt. 16: 16-20). However, He was never called or accepted to be addressed by that title in His lifetime on Earth.
Whereas the name Jesus Christ is recurrent in the New Testament, the phrase “Ἰησοῦς ὁ χριστός” i.e. “Jesus the Christ” or in Hebrew “Yeshua Hamashiach” seems to appear only once in the New Testament–depending on which cordex you use.