Christ is not Jesus' last name! Palestinian Jews of the 1st Century did not have surnames. Since you would most likely have shared your name with many others, you were distinguished by identifying your father: "James the son of Zebedee...James the son of Alphaeus" (Matthew 10.2-3, ESV), or, as in the case of "Jesus of Nazareth," by identifying where you were from (Luke 4.16, 34, ESV).
Christ is not a surname but a title. That is why he is so frequently called "Christ Jesus" or can simply be referred to as "the Christ" (Romans 1.1; Mark 8.29, ESV). Many Christians recognize the title "Christ" as equivalent to "Messiah." That's true. The label "Christ" is the New Testament Greek equivalent of the Old Testament Hebrew term "Messiah." In fact, in some English Bibles the word "Messiah" appears instead of "Christ" in some New Testament passages (Mark 8.29, HCSB, NLT, NIV 2011).
The fact is, however, that neither "Messiah" nor "Christ" is an English translation. Rather, both terms are examples of transliterations. With the word "Messiah," the original Hebrew letters have been changed (transliterated) into the equivalent letters in the English language. When you read or say "Messiah," you are in essence reading and speaking Hebrew. With the word "Christ," the original Greek letters have been changed (transliterated) into the equivalent letters in the English language as well. So again, when you read or say "Christ," you are in essence reading and speaking Greek.
The problem with transliterating words instead of translating words is that the reader may remain unaware of what the word he is reading actually means! The process of translation involves learning the meaning of the word in its original language and then finding a word (or words, if necessary) that effectively conveys (or convey) the same meaning in one's own language. "Christ" is an accurate translation of "Messiah" only if you speak Greek! (See John 1.41, ESV.) Neither "Messiah" nor "Christ" is an accurate or meaningful translation for an English speaker because neither word is intended to be an English translation but only a transliteration into English.
So what does "Messiah" mean? What does "Christ"mean? And what English word (or words) best captures (or capture) that meaning for the native speaker of English? How should it be translated in our English Bibles? Both "Messiah" and "Christ" denote anointing, being anointed, or the anointed one (Psalm 2.2, ESV). According to the fourth edition of the American Heritage Dictionary, anoint means "1. To apply oil or ointment to, esp., in a religious ceremony. 2. To choose by or as if by divine intervention."
In the Hebrew Scriptures, anointing was practiced to initiate men into three separate offices. Kings and priests were anointed with oil by their fellow Israelites according to God's instruction (Exodus 29.7, 21; 1 Samuel 10.1; 16.12, ESV). Prophets were anointed with the Holy Spirit by God. Kings could be prophets (like David or even Saul) and be anointed with oil and the Spirit (1 Samuel 10.9-13; 16.13, ESV). Priests could also be prophets (like Ezekiel, although he never served in the Jerusalem temple) and also be anointed with oil and the Spirit (Ezekiel 1.3, ESV). But kings could never be priests, nor could priest ever serve as kings (Numbers 18.7; 1 Samuel 13.8-14; 2 Chronicles 26.16-21, ESV).
Only One Person would ever hold all three offices. Only One would ever be anointed as prophet, priest, and king simultaneously. Only One would ever fulfill the meaning and significance of all three offices. Only One would not only fulfill those three roles but "fill them full." Only One would ever be anointed to fill all three roles perfectly. Only One would be anointed to fill those three offices eternally and permanently. He, of course, is Jesus the Anointed One! The Anointed Jesus is our Prophet-Priest-King! I do not say "prophet, priest, and king" because those offices are now made one in him and in him alone. He was not anointed on three separate occasions to three separate offices. He was anointed once for all! (See Luke 3.21-22; 4.16-21; 9.28-36, ESV.)
This precious truth is what is at stake if we mistakenly go on thinking of "Christ" as Jesus' last name. It does our Anointed Lord great disservice to perpetuate this misunderstanding by an inadequate and insufficient mere transliteration of his glorious title that speaks so highly of his incomparable Person and work!