The Mystery of God

Ephesians 1:9,10  Having made known unto us the mystery of his will, according to his good pleasure which he hath purposed in himself: That in the dispensation of the fulness of times he might gather together in one all things in Christ, both which are in heaven, and which are on earth; even in him:

Not only did God adopt us unto the good pleasure of His will, but He also purposed in His will to gather together all things into one in Christ. The mystery of His will, which He planned for His own pleasure was revealed or has been made known unto us His children. The word mystery means to shut the mouth or keep silent. There are several mysteries in scripture where God keep silent and did not give explicit details about a truth in His will. Notice, 1 Corinthians 4:1  Let a man so account of us, as of the ministers of Christ, and stewards of the mysteries of God. At this point let me briefly mention seven mysteries of God.
1.) Mystery of Godliness - this is about the fact that God would come in human flesh and do the work necessary for salvation. 1 Timothy 3:16  And without controversy great is the mystery of godliness: God was manifest in the flesh, justified in the Spirit, seen of angels, preached unto the Gentiles, believed on in the world, received up into glory.
2.) Mystery of Israel's blindness - this is about the fact that Israel is blinded to the gospel for a time while the Gentiles are able to see.  Romans 11:25  For I would not, brethren, that ye should be ignorant of this mystery, lest ye should be wise in your own conceits; that blindness in part is happened to Israel, until the fulness of the Gentiles be come in.
3.) Mystery of the Church - this is about the fact that the church (a local assembly of believers) are the body of Christ to continue on the ministry Christ started.  Ephesians 5:32  This is a great mystery: but I speak concerning Christ and the church. 
4.) Mystery of Iniquity - this is about the fact that Satan is already working in deceiving people to sin and reject Christ. 2 Thessalonians 2:7  For the mystery of iniquity doth already work: only he who now letteth will let, until he be taken out of the way.
5.) Mystery of the Rapture - this is about the fact that one day believers will be caught up and changed in a twinkling of an eye. 1 Corinthians 15:51  Behold, I shew you a mystery; We shall not all sleep, but we shall all be changed...
6.) Mystery of Babylon - this is about the fact that there is a false religious system that the Antichrist will use. Revelation 17:5  And upon her forehead was a name written, MYSTERY, BABYLON THE GREAT, THE MOTHER OF HARLOTS AND ABOMINATIONS OF THE EARTH.
7.) Mystery of Christ - this is about the fact that Christ would be in us. Now here is where this ties into our text verse. In Ephesians chapter 3 the mystery is described in more detail, but I will summarize it as the Jew and Gentile being one in Christ. Notice what is says, Ephesians 3:3,4  How that by revelation he made known unto me the mystery; (as I wrote afore in few words, Whereby, when ye read, ye may understand my knowledge in the mystery of Christ) and then verse 6 says, That the Gentiles should be fellowheirs, and of the same body, and partakers of his promise in Christ by the gospel: The mystery of Christ is the fact that because God's seed (Jesus Christ) abides in us, we are thus of the seed of Abraham. Being of the seed of Abraham by faith in Christ allows Jew and Gentiles to be one.  In totality Christ is going to one day restore everything in one and perfect unity, undoing the results of the fall. Paul speaks more of this mystery in Colossians 1:25-27  "Whereof I am made a minister, according to the dispensation of God which is given to me for you, to fulfil the word of God; Even the mystery which hath been hid from ages and from generations, but now is made manifest to his saints: To whom God would make known what is the riches of the glory of this mystery among the Gentiles; which is Christ in you, the hope of glory:"  Think about it! We have the hope of glory living within us! Why be discourage, fearful or dismayed?  We have a glorious hope!!! Christ lives in us! We shall be, nay rather are victorious! Amen!!