Emphasis on Psalm 23
There is something about this Psalm 23 that tells us that truly David is a man of strong faith in God...

The Lord is my shepherd
I shall not want
(The writer recognized the fact that God is His provider and has this very strong assurance that he would'nt lack ).

"He maketh me to lie down in green pastures: he leadeth me beside the still waters.
( King David is saying here that the Lord has blessed and provided him with a bountiful harvest)

He restoreth my soul: he leadeth me in the paths of righteousness for his name's sake.
( The devil the prince of this world has taken possession of so many souls till date but David acclaimed and know's that the Lord has taken charge of his soul by restoring it).

"Yea, though I walk through the valley of the shadow of death, I will fear no evil: for thou art with me; thy rod and thy staff they comfort me.
(David knew at this time he is passing through a difficult times but in all he is more than a conqueror through God. The success we achieve after a difficult trial makes us a better Christian)

Thou preparest a table before me in the presence of mine enemies: thou anointest my head with oil; my cup runneth over.
( wow this is powerful, this the best prayer we should always be praying for our enemies. The writer knew even though he had alot enemies but the Lord lifted him in their presence and enlarged his coast).

Surely goodness and mercy shall follow me all the days of my life: and I will dwell in the house of the LORD for ever.
(David also has a this great confident that he said "surely" he did'nt just said goodness and mercy shall follow him but he knew for sure they will follow him. And he ended it by saying he will dwell in the house of the Lord forever meaning " he will never leave God's presence".

But David could have decided not to serve the Lord because he has all the comfort and riches of this world, but he was wise, he never failed to recognise God.