The Multiple Mysteries of Human Nature.

Human nature contains several mysteries or secrets concerning the existence and purpose of the human race. 

1) If man is composed of an immortal soul and a body and when man dies, he will continue to exist forever without a body and then man's existence is dominated as a life of a pure spirit. Such a life is outside sequential time as a measure of accidental change of bodies. Therefore the separated soul continues to live in time similar to that of the angels, called aeveternity, or if the soul sees God face to face, then eternity. The continued existence of the man without a body is a mystery concerning 1) the current union of body and soul and 2) the ongoing life of man with a separation of body and soul. 

2) If man is composed of an immortal soul and a body and when man dies he will continue to exist for a time without a body until the general resurrection. The general resurrection of man to restore man back to his integral nature is a mystery of the ongoing existence of man who is dependent upon the power and wisdom of God to cause the reunion of body and soul. Man then has his life here and now, then dies and lives another life in the spirit realm, and then lives a third life when reunited as body and soul. Each state of life is then a mystery in itself and a mystery in relation to the other states of life.

3) If man is only a material substance,  man ceases to exist at death and man's existence is only a temporal event without any permanent and lasting value. The existence of man and the universe is then a mystery of futility, whilst the universe continues to exist. All things then exist for no reason, when in fact if nothing existed, the negation would also serve the same futile purpose. The futile universe of the materialist is a universe with the equivalent value of a pure negation of all things. Such a universe containing the materialist man is a mystery.

The entire big picture of man as a creature with incomplete substantial parts of body and soul is also a mystery, for the entire show need not exist apart from the will of God that causes all things to exist and God's providence that causes all events to occur in accord with His plan.