The "Mystery" of God is the revelation of the Wisdom of the Will of God, revealed by God to His original Messengers: the Patriarchs, the Prophets, the Righteous, who testified to it in the Holy Scriptures and through evangelism revealed it to the nations to establish their lives in righteousness.

"Mystery" is the unknown, inaccessible physical and spiritual goods to sinfully thinking and living man, received, felt, realized by man exercising "...the wisdom of God, secret, hidden." (1 Corinthians 2:7)

"Mystery" is also the development of future historical events, which cannot be foreseen, described, understood, using knowledge not based on the revelations of Divine Laws, of the Divine Will.

 It is also a symbol of the physical Laws of the infinite Divine Universe not comprehended by man, which cannot be revealed to him in their entirety.

 Negative meaning.

"The "mystery" to the nations of the sinful world is that by rejecting the Teachings of Jesus Christ, they have not thereby accepted, recognized the true Messiah, Jesus Christ.

"The mystery of iniquity," "the mystery of the woman," "the mystery of the beast" are the causes of iniquity, the essence of false beliefs and violent political systems, unknown to sinfully thinking man.

"Mystery" is the perception by sinfully thinking man, who rejects the Will of God, of false beliefs as true, of his own lawless actions as true, of the totality of his lawless, ungodly way of life as true, right. 

The "mystery" for the man who does not do the Will of God, who lives in the darkness of total spiritual ignorance, is the true meaning and purpose of his life.