1 The LORD is my shepherd, I shall not be in want. 2 He makes me lie down in green pastures, he leads me beside quiet waters, 3 he restores my soul. He guides me in paths of righteousness for his name's sake. 4 Even though I walk through the valley of the shadow of death, I will fear no evil, for you are with me; your rod and your staff, they comfort me. 5 You prepare a table before me in the presence of my enemies. You anoint my head with oil; my cup overflows. 6 Surely goodness and love will follow me all the days of my life, and I will dwell in the house of the LORD forever. - Psalm 23

"The LORD is my shepherd"
Shepherd is a descriptive title. It mentions kind of job and relationship in one word. A managerial role over a group of followers with responsibilities for their care and protection. For Believers in Christ Jesus we are His sheep and He is our shepherd, but not just any shepherd. He is our Great Shepherd. 
The LORD is called "great shepherd" in Hebrews 13:20 in reference to this Psalm due to that spiritual magnitude of His role over those who accept Him as Lord and Savior.

"I shall not be in want"
This condition is because if you have a relationship with the Great Shepherd you have everything. Paul really stresses this in several of his letters - Philippians 4:11, 12; 1 Timothy 6:6, 8 and Hebrews 13:5. The Philippians 4:12 verse says, "
I know what it is to be in need, and I know what it is to have plenty. I have learned the secret of being content in any and every situation, whether well fed or hungry, whether living in plenty or in want." However, within His fold, flock, and/or Kingdom there are many additional Benefits - 

1.  "He makes me lie down in green pastures"
Pastures are for sheep to lounge, graze and socialize - otherwise known as food, fun and fellowship to some. The Great Shepherd operates in a provisional role here. He treats His sheep to "green pastures", representing the opportunity for the sheep, His Believers to graze and rest or "lie down in" - to enjoy His presence and the presence of other believers. Two other Scriptures come to mind - Matthew 11:28 - 
“Come to me, all you who are weary and burdened, and I will give you rest." And the prayer for our daily provision of His Word and material blessings in Matthew 6:11Give us today our daily bread.

2.  "He leads me beside quiet waters" 
To a sheep, "quiet waters" would nourish the inside with nice, cool, refreshing water and calm the outside by being a pleasant sound to hear.  It would also not drown out any potential predatory threats like raging waters or rapids would.  Another couple of Scripture passages the Holy Spirit equated with this image were - "Peace I leave with you, my peace I give unto you: not as the world giveth , give I unto you. Let not your heart be troubled , neither let it be afraid." (John 14:27)  Concerning "quiet waters" that anyone would want to dwell beside or drink from -"Jesus answered, "Everyone who drinks this water [water from a human well] will be thirsty again, but whoever drinks the water I give him will never thirst. Indeed, the water I give him will become in him a spring of water welling up to eternal life." (John 4:13-14)  The Words of Jesus are indeed The Bread of Life and The Living Water of the soul and the "quiet waters" is a great place for meditation and nourishment from the River of Life Himself - Jesus.

3.  "He restores my soul" 
As a shepherd might console or comfort a sheep that is agitated about something so does the believer's Great Shepherd with His flock. John 14:16 does an excellent job in describing the Spirit of Christ as a "restorer of our souls"; as a comforter -  And I will pray the Father, and he shall give you another Comforter, that he may abide with you for ever;  Jesus is also known as the Prince of Peace (Isaiah 9:6) and through the power of the Holy Spirit He ministers to the believer when needed. However, the ultimate restoration comes for the "whosoever will believe" at the moment of accepting Christ as their personal Savior (John 3:16).  Jesus has taken the condition of everyone's soul - Broken - and restored it for eternity.

4.  "He guides me in paths of righteousness for his name's sake." 
A regular human shepherd would guide a sheep along the right path.  The Great Shepherd of the Believer in Christ not only leads us along the right path, but the path we traverse is of "righteousness" or right doing and it is "for his name's sake" or for the Glory of God that we do. Paul supports this nicely in his first letter to the believers in Corinth - "So whether you eat or drink or whatever you do, do it all for the glory of God." (1 Cor. 10:31). Notice too that sheep may bear a mark of their shepherd.  The Believer has the responsibility of carrying and representing the name of Jesus Christ - Christian.  The Lord guides the true Believer along the journey of life in doing the right thing so that other people might say, "Hey, He/She must be a Christian because that lines up with what the Bible and I have believed a Christian should do." Just as sheep or any other animal would be branded, His brand, His name we bear, use it wisely and not in vain!

5.  "Even though I walk through the valley of the shadow of death, I will fear no evil, for you are with me;"  
Wow!  There is the "shadow of death" and then just when you though it couldn't get any worse there is "the valley of the shadow of death"!  And even though believers may reach a point in their lives where they are facing their mortality or perhaps evil itself - there is no need for any kind of fear, including the fear of evil because The Great Shepherd is with the believer. In fact, The Great Shepherd has hand-held devices that aide in moments like these.

6.  "your rod and your staff, they comfort me."
I can hear a sheep saying now - "Really? A rod and a staff are going to comfort me? Prove it to me?" I also can hear us as believers submitting the same question. The Staff or hooked "J" pole that we commonly see shepherds pictured with were used to guide sheep or pull them back from danger. A Rod or straight pole/club was meant for discipline within the fold and protection of the fold. So it is with the Great Shepherd of believers in Christ. He does the same mentally, physically, and spiritually for His sheep/followers.

   7.  "You prepare a table before me in the presence of my enemies." 
Being a sheep I am overjoyed that My Great Shepherd is the one "preparing the table". I am also elated that lamb is not on the menu! No!  On the contrary!  The table is prepared before my enemies so they can see that I have "tasted of the Lord and He is good!" (Psalm 34:8).  They will see that I and many other Believers have partook of the Lord's Table, believing in The Sacrificial Lamb - Jesus. This Lamb of God was placed on the plate to be devoured in our place once and for all (John 1:29).

8.  "You anoint my head with oil"
This is a special sheep for sure, if you keep that theme here. From a sheep to a priest! In the Old Testament whenever a Priest or King was ordained, someone anointed him. Revelation 20:6 views the Believer as Priest, anointed to rule and reign with Christ during the Millennial Reign of Christ on earth - "Blessed and holy are those who have part in the first resurrection. The second death has no power over them, but they will be priests of God and of Christ and will reign with him for a thousand years." Also, oil was used to anoint someone for the healing of an ailment. Here, our Great Shepherd is the anointer and we are the anointed - to be healed and to go be Priests for Him.

9.  "my cup overflows"
For the sheep, I guess "my cup" would be a trough. The Great Shepherd has done everything for the sheep or believer in this Psalm. There are times in our lives when we need to not only stop and smell the roses, but we need to pause and know that He is God (Psalm 46:10). With good attention and merciful behavior from any regular shepherd the sheep are sure to flourish.  How much more so the sheep/believers under the care of the "goodness and mercy" of The Great Shepherd!  And not just this....

"and I will dwell in the house of the Lord forever.
Wow! Quite a step up from the pasture, eh? From all the descriptions in the Book of Revelation His house is to die for! 
The Lord has taken the sting out of death by conquering it, the grave and hell. Now, because of His victory His House becomes our pasture. Psalm 27:4 does a beautiful job saying that - "One thing I ask from the Lord, this only do I seek:  that I may dwell in the house of the Lord all the days of my life, to gaze on the beauty of the Lord and to seek him in his temple."

Truly, truly I say unto you, we are His sheep and He is The Great Shepherd!