To ponder these words is not an original idea.  Just by changing the emphasis as they are spoken is to begin to consider the fullness of the truth therein contained.  The LORD is my shepherd. It is one thing to have a shepherd and something totally different yet to consider that the Shepherd is the LORD.  Him Who sits upon the throne of all creation (in Him, by Him, through Him, and for Him were all things created) is my shepherd.  There is great comfort in knowing the Shepherd.  Since He is the shepherd and I am the sheep of His pasture then learning of sheep could be of benefit.  Sheep are woefully ignorant and much afraid.  That would be a most kind rendition of humankind in general and Christians in particular.  Remember that we are the proud possessors of a reprobate mind (one that has been tested and found to be no good) and that the wrath of God is being revealed against "all" ungodliness and "all" unrighteousness without exclusion!  In case you missed it, "sin" is the wrath of God inflicted!  Why is this important?  Because I have need of a shepherd and that need has been fulfilled in a most remarkable way!  The LORD is my shepherd.  I could say that I have a renewed mind, but that would not be true!  The renewing of the mind is a continuous operation of the Holy Spirit and is necessary because in my flesh there lies no good thing.  So when sin enters my life (and believe me it does!) I have need of this wondrous Shepherd who will always draw me back to Himself!  I can never be lost for I am found!  The LORD is my shepherd, the alternative is unthinkable!