The apostle Paul directs our thoughts to unity.
EPHESIANS 3:1-13 (World English Bible)
“For this cause I, Paul, am the prisoner of Christ Jesus on behalf of you Gentiles, if it is so that you have heard of the administration of that grace of God which was given me toward you, how that by revelation the mystery was made known to me, as I wrote before in few words, by which, when you read, you can perceive my understanding in the mystery of Christ, which in other generations was not made known to the children of men, as it has now been revealed to his holy apostles and prophets in the Spirit, that the Gentiles are fellow heirs and fellow members of the body, and fellow partakers of his promise in Christ Jesus through the Good News, of which I was made a servant according to the gift of that grace of God which was given me according to the working of his power. To me, the very least of all saints, was this grace given, to preach to the Gentiles the unsearchable riches of Christ, and to make all men see what is the administration of the mystery which for ages has been hidden in God, who created all things through Jesus Christ, to the intent that now through the assembly the manifold wisdom of God might be made known to the principalities and the powers in the heavenly places, according to the eternal purpose which he accomplished in Christ Jesus our Lord. In him we have boldness and access in confidence through our faith in him. Therefore I ask that you may not lose heart at my troubles for you, which are your glory.”
I have never been real fond of surprises. I am typically the person who likes to know what will happen so I can plan my day. It was years ago that my then-girlfriend, now wife, planned a surprise birthday party for me. The thing, though, is that it was not a surprise to her. She knew what she was planning and doing.
Paul mentions a mystery revealed in his letter to the church. The mystery of Christ, which in past generations was concealed, has now been made known to Christs' apostles. The secret, Gentiles are part of the body of Christ and partakers of His promises. Through Paul's letters, we notice the importance of unity. We see the importance of the body of Christ being one.
The good news of the message of Christ is now accessible to everyone. Paul spent his life sharing the message of Christ in hopes that others would respond to the promises that are in Christ. The unsearchable, rich, and generous promises of Christ that bring us to be one in Him.
The mystery of Christ kept hidden in times past has now been revealed. Although people were unable to see it, God has known what He has been planning and doing through the ages.
We may not fully comprehend the mystery of Christ, His love, the depth of His plan; however, this should not keep us from responding to His good news.