John tells us in Revelation 10:7 that in the days of the seventh angel, when he is about to sound, that is: before the seventh trumpet was blown, the mystery of God would be complete. What, then is the mystery of God? Well, as it turns out, there are several mysteries of God, and the Apostles, Paul, and the other New Covenant writers are the stewards of what is called the mysteries of God (1Corinthians 4:1; Ephesians 3:4-5). Jesus told his disciples that the world could not understand these mysteries, because it was given that only his disciples would know them (Matthew 13:11; Luke 8:10; in Mark 4:11 it is put in the singular). The Gospel, which is the preaching of Jesus Christ, is the mystery (of God), which was kept secret since the world began, is now revealed according to the command of God, and is to be made known to the nations for obedience through faith (Romans 16:25-26).
One of the mysteries that was revealed to the authors of the New Covenant Scriptures was that blindness, but only in part, had occurred to Israel, until the fullness of the gentiles would come to Christ (Romans 11:25). This occurred, because the Jews had rejected Jesus as their Messiah, so he was to be offered to the whole world as a result of that rejection. Likewise, the mystery that gentiles should be fellow heirs, of the same body and partakers of the Messiah through the Gospel was also revealed to the Apostles and prophets by the Spirit of God (Ephesians 3:3-9).
If a man speaks the mysteries of God, he speaks in an unknown tongue, which means he cannot be understood, unless what he says is interpreted in words easy to understand by the folks listening to him. Although, while speaking in an unknown tongue he is still able to communicate with God, and he is able to be edified thereby, unless he or another is able to interpret what he speaks, no one else is able to understand even though his literal language is the language of the people to whom he speaks or writes (1Corinthians 14:2, 4-5, 13, 27-28). In other words, Paul is saying it is very difficult to speak the mysteries of God clearly, so others are able to understand. This is why Paul coveted the prayers of the saints, because he desired to be able to open his mouth and speak clearly to others and make known the mystery of the Gospel (Ephesians 6:19, cf. Colossians 4:3).
Paul tells us that the writers of the New Covenant spoke the wisdom of God in a mystery. That is, they spoke the hidden wisdom of God, which had been kept secret since before the world began. That wisdom had no real context in the worldviews of the people in the world, including the Jews, so understanding it was made possible only through the indwelling of the Spirit of God, which searches all things. However, the natural man, who doesn’t have God’s Spirit, cannot understand the mysteries, as they are preached in the New Covenant Scriptures, because they are spiritually discerned (1Corinthians 2:7, 10, 14).
Another mystery that Paul revealed is that at the coming of Christ we would not all sleep, but all will be changed. At the last trump the dead in Christ would rise, and we, who are alive, would be changed. That is, this corruptible must put on or be clothed by incorruption, and this mortal must put on or be clothed by immortality. In other words we must put on Christ. In so doing, the saying ‘Death is swallowed up in victory’ is fulfilled. (1Corinthians 15:51-54).
Another mystery revealed in the New Covenant Scriptures is that God would gather together in one all things in Christ, i.e. all things in heaven and in earth. In other words, heaven and earth would be reunited, as it was in the beginning before Adam was cast out of Eden / the Most Holy Place (heaven), where the presence of God dwelt.(Ephesians 1:9-10; cf. John 14:3). The Gospel Christ has restored the presence of God with men (cf. Revelation 21:3). In other words, the mystery that had been kept secret in the previous age, but was made known to the saints in this present age, was that mankind’s hope of glory is Christ in you, that is Christ in all the nations (Colossians 1:26-27).
Paul revealed in his Gospel that in Christ is hid all the treasures of wisdom and knowledge. (Colossians 2:2-3), and as children of God we have access to this, our inheritance, while IN Christ (Ephesians 1:3). This is fully realized in the revelation of another mystery of God that concerns Christ and the church (Ephesians 5:32). It has to do with submitting ourselves, one to another (Ephesians 5:21). Wives, meaning the local body of believers, are to submit to their husband (the pastor), as unto the Lord. For the pastor is the head of the local body of believers, even as Christ is the head of the entire church (Ephesians 5:22-25). This is done in order that Christ might present the whole church to himself without spot by cleansing it with the word of God (Ephesians 5:26-27). The local body of believers and the pastor grow together in Christ as though they were husband and wife (Ephesians 5:28-31).
 My next study: The Mysteries of Godliness and Iniquity will complete my study on the Mysteries of God.