Deut.29: The secret things belong unto the LORD our God: but those things which are revealed belong unto us and to our children forever, that we may do all the words of this law.
There were certain things God did not reveal to humanity during the days of the Old Testament. These things were hidden among the Godhead. In the revealing of the faith of the New Testament God made these things known to the church. In the Pauline Epistles they are referred to as mysteries.
In no less than four of the Pauline epistles are we told these things have been hidden in God before mankind was created and not revealed until revealed to the church.
Col.1: Even the mystery which hath been hid from ages and from generations, but now is made manifest to his saints:
Eph.3: Which in other ages was not made known unto the sons of men, as it is now revealed unto his holy apostles and prophets by the Spirit;
Eph.3: And to make all men see what is the fellowship of the mystery, which from the beginning of the world hath been hid in God, who created all things by Jesus Christ:
Rom.16: Now to him that is of power to stablish you according to my gospel, and the preaching of Jesus Christ, according to the revelation of the mystery, which was kept secret since the world began,
1Cor.2: But we speak the wisdom of God in a mystery, even the hidden wisdom, which God ordained before the world unto our glory:
In Galatians chapter three we find:
Gal.3: But before faith came, we were kept under the law, shut up unto the faith which should afterwards be revealed.
Just as God revealed Himself through the Old Testament law so He reveals Himself to the church through the revelation of these mysteries. These mysteries contain the wisdom of God for our Christian faith. It is the essence of our Christian doctrine. Understanding of these mysteries makes for a Christian strong in the faith. The misunderstanding makes for a weak in the faith Christian.
It is these mysteries which may be used to identify true doctrine from false doctrine. The majority of false doctrines stems from no understanding, denial of or a false understanding of these mysteries.
These mysteries establish a person as a steward of God. We find in First Corinthians and First Timothy the following:
1Cor.4: Let a man so account of us, as of the ministers of Christ, and stewards of the mysteries of God.
 Moreover it is required in stewards, that a man be found faithful.
1Tim.3:  Likewise must the deacons be grave, not doubletongued, not given to much wine, not greedy of filthy lucre;
 Holding the mystery of the faith in a pure conscience.
In future studies we will identify and explain these mysteries and their relevance to the Christian.