The prophecy of Psalm 23 describes the LORD (all caps) as “my shepherd.” The term “LORD” in Hebrew is Yahweh. Jesus is called both “Lord” and “Shepherd” in the New Testament–therefore, it is clear that the object of this first verse from the twenty-third Psalm is the Messiah, Jesus.
Psalms 23:1 “The LORD is my shepherd; I shall not want.”
In the Old Testament, the term LORD in Hebrew is Yahweh.
In the New Testament, the word Lord in Greek is Kyrios.
Kyrios is often used as a polite way to address a person, such as when we address a man today as “sir.” It can also mean “master,” as in one who rules over a servant or slave. The Greek translation of the Old Testament called the Septuagint was widely used during the time that Jesus was here on the earth. The Greek word Kyrios in the Septuagint was translated from the Hebrew word, Yahweh or Jehovah–the Old Testament name for God. Whenever Jesus is addressed as “Lord” in the New Testament, the intent is to identify Him as Yahweh.
The Greek, Kyrios, is used in the Septuagint translation of the Hebrew scriptures 6,814 times. Yahweh is the One God of the universe  This is important because it is also used in translating the name for God, Yahweh, in applying the name for God to Jesus in the New Testament. Kyrios is found in the Koine-Greek New Testament 740 times, and nearly always refers to Jesus as Yahweh.
Anyone who spoke Greek during the first century, understood that Jesus designation as Lord in the New Testament was the same person described in the Old Testament as Yahweh. There are several places in the New Testament where Jesus is called Yahweh. Clearly, the New Testament translators intended that readers of the Greek New Testament—understand that Jesus is Yahweh.
Luke 2:11 For there is born to you this day in the city of David a Savior, who is Christ (Messiah) the Lord (Yahweh). 
A Jew who read this Greek New Testament account of the angel’s announcement to Mary, that her Son would be the Messiah, Yahweh of the Old Testament, would be shocked and amazed. Nevertheless, this is what the original language demands, as it is written.
“Today, in the city of Bethlehem, the baby who has been born is the Messiah, who is God Himself.” This is why the shepherds were so amazed at the angel’s statement.
Jesus Referred To Himself As “The Shepherd” of Psalm 23
John 10:11 “I am the good shepherd. The good shepherd gives His life for the sheep.”
John 10:14-15 “I am the good shepherd; and I know My sheep, and am known by My own. As the Father knows Me, even so I know the Father; and I lay down My life for the sheep.”
Jesus took the term “Shepherd” one step further. He claims to be The Door, the single entrance into heaven. He says that all those who came before Him were impostors, and that no one else has the authority to grant eternal life, other than He. At the original Tabernacle in the desert, there was just one entrance—a single way into the place of sacrifice and salvation. No one could come through this single door to the Tabernacle without first having a sacrifice for their sins. See Prophecy 332 for a detailed description of the Tabernacle.
John 10:7 −9 Then Jesus said to them again, “Most assuredly, I say to you, I am the door of the sheep. All who ever came before Me are thieves and robbers, but the sheep did not hear them. I am the door. If anyone enters by Me, he will be saved, and will go in and out and find pasture.”
This is a bold statement considering that there are hundreds of churches, religions and religious leaders who claim to be the only way to heaven. Who is right? How can we know who is telling the truth? In John chapter 10, Jesus supports His claim that only He can grant eternal life—by the stunning evidence of His resurrection. Before He was crucified, Jesus promised that He would be raised to life three days later.
Mark 8:31 “And He began to teach them that the Son of Man must suffer many things, and be rejected by the elders and chief priests and scribes, and be killed, and after three days rise again.”
John 11:25-26 Jesus said to her, “I am the resurrection and the life. He who believes in Me, though he may die, he shall live. And whoever lives and believes in Me shall never die. Do you believe this?”
When David wrote the 23rd Psalm, he did so as a shepherd himself. He understood that what he had written, was given to Him by God, describing the Shepherd of the 23rd Psalm as the coming Messiah. David wrote in later verses that the Messiah would be resurrected from the dead and rule the world as King of kings and Lord of lords. We know that this is true as Peter confirms Jesus resurrection as an event known to David when he wrote the prophecies of the Psalms.
Acts 2:29-32 “Men and brethren, let me speak freely to you of the patriarch David, that he is both dead and buried, and his tomb is with us to this day. Therefore, being a prophet, and knowing that God had sworn with an oath to him that of the fruit of his body, according to the flesh, He would raise up the Christ to sit on his throne, he, foreseeing this, spoke concerning the resurrection of the Christ, that His soul was not left in Hades, nor did His flesh see corruption. This Jesus God has raised up, of which we are all witnesses.”
 Strong’s Hebrew Concordance # 3068
 Strong’s Greek Concordance # 2962
 This title is given α. to God, the ruler of the universe (so the Sept. for אֲדֹנָי, אֱלוהַּ, אֱלֹהִים, יְהוָה, and יָהּ;, from Strong’s 2962, “Kyrios,” and Thayers Greek Lexicon.
1. κύριος. Liddell, Henry George; Scott, Robert; A Greek–English Lexicon at the Perseus Project.
4. The Christology of the New Testament by Oscar Cullmann 1959 ISBN 0-664-24351-7 pages 234-237
5. The Bauer lexicon, 1979 edition
6. Philip Schaff. “LORD”. New Schaff-Herzog Encyclopedia of Religious Knowledge, Vol. VII: Liutprand – Moralities. p. 21.
7. Archibald Thomas Robertson. “10”. Word Pictures in the New Testament – Romans.