The reality of God, Christ, and the Holy Ghost

There are a lot of scripture mastery verses found in Doctrine and Covenants section 130.  Today's verses also come from there.  Verses 22 and 23 are today's scripture mastery.  They teach us more about the relationship between God, his Son, Jesus Christ, and the Holy Ghost:

22 The Father has a body of flesh and bones as tangible as man’s; the Son also; but the Holy Ghost has not a body of flesh and bones, but is a personage of Spirit. Were it not so, the Holy Ghost could not dwell in us.

23 A man may receive the Holy Ghost, and it may descend upon him and not tarry with him.

I have discussed this topic in a few previous posts.  For example: "We are created in God's image," and "Moses saw God face to face," and "Steven sees Christ standing on the right hand of the Father."
  God is real.  So is His Son, Jesus Christ.  They each have physical bodies, just as we do--though theirs are perfect and glorified, while ours have not been.  We are subject to disease and death, while the bodies that they have are not.  The Holy Ghost is also a member of the Godhead (What other Christian faiths often refer to as the Holy Trinity.)  The Holy Ghost does not have a physical body, though he does have a spirit body.  God the Father, God the Son, and God the Holy Ghost--they are all part of this Godhead, or Trinity.  They are separate beings, though they are completely unified in purpose and in their love for us.  In fact, of all the creations of God, we are the most important to Him.  He has said "This is my work and my glory—to bring to pass the immortality and eternal life of man." (Moses 1:39)

What did verse 23 mean?  Why would the Holy Ghost "descend upon" somebody and not "tarry with" them?  I understand that to mean that anybody can receive the promptings and teachings of the Holy Ghost--irrespective of what religion they belong to.  The Holy Ghost has as one of His primary objectives to teach us right and wrong.  Some call His influence our conscience.  We all have a conscience.  It has also been called the "Light of Christ."  That innate knowledge that we all have that tells us the difference between right and wrong is the Holy Ghost.  That can be lost.  If we continually ignore the promptings of our conscience (the Holy Ghost)  He eventually stops prompting us. . .

Wouldn't it be great to always have the presence of the Holy Ghost?  To always have a member of the Godhead to be with us to teach us and guide us?  We can!  When baptized in to the Church with the proper authority (the Priesthood power of God) we are given a wonderful gift.  It is called the gift of the Holy Ghost.  What that means is that if we are righteous, we can have the presence of the Holy Ghost to be with us always--not just in fleeting moments.  To be worthy of that gift, we must listen to the promptings of the Holy Ghost, and obey the commandments of God.  If we do, we can have the constant presence and guidance of the Holy Ghost in our life.