In the New Testament the Greek word for mystery, musterion, occurs twenty-eight times. Twenty-one are in the writings of the Apostle Paul. Mystery is vital to Christian faith and understanding. Yet the concept has been frequently misunderstood too.

The best theology has always maintained that what is known must be balanced by what is not clearly known. God is a mysterium trememdum et fascinans, compelling the worshiper with awe toward him but remaining ultimately beyond the grasp of human reason and imagination. The so-called mystical tradition, which uses all the available means to approach God (reason, prayer, meditation, spiritual imagination, the sacraments, etc.), finds its biblical roots in a text like Colossians 2:2–3:

My goal is that they may be encouraged in heart and united in love, so that they may have the full riches of complete understanding, in order that they may know the mystery of God, namely, Christ, in whom are hidden all the treasures of wisdom and knowledge.

It was once thought that Paul was using this term to connect with esoteric and mystery religions in his missional context but most biblical scholars now concur that it was used to speak about something previously hidden but now revealed (cf. Col. 1:26–27; 1 Cor. 2:1; Eph. 6;19). In this sense divine mystery is virtually shorthand for the gospel. Yet the word is also used to describe a degree of continued hiddenness. In fact, when used in relationship to divine revelation, Stephen Motyer says the term seems to convey the idea of ultimate ungraspability (cf. 1 Cor. 2;7; 13:3; Eph. 5:32 and Colossians 2:2-3 as noted above). Thus the term has two sides to it–revealed and hidden. This is not contradictory. It corresponds to two facts regarding all our knowledge of God. His judgments are unsearchable and his ways inscrutable (Rom. 11:33) and yet “he [has] made known to us in all wisdom and insight the mystery of his will” (Eph. 1:9, RSV). 

Desmond O’Donnell rightly says, “A mystery in the New Testament is something so deep that it is endlessly rich. Our only approach to a Christian mystery is to accept our inability to fully comprehend the richness and depth of its beauty.” 

Paul speaks of “the mystery of Christ” and “the mystery of God” and “the mystery of faith” and “the mystery of God’s message.” In the Colossians text above Paul says he wants our hearts to be encouraged and united in love so that we may have all the riches of assured understanding and the “knowledge of God’s mystery which is Christ himself.” 

We are not apostles yet we too share, by he Spirit, in this same mystery, the very mystery given to Paul and the Apostles of our Lord. In fact, we are servants of this mystery. We do not receive it directly by human means but by revelation and prayer. We must discipline our minds and hearts to contemplate this mystery more deeply if we are to receive it and share in it as good stewards of the mystery of the gospel.