1 Corinthians 2 v 7


1 Corinthians 2:7 
But we speak the wisdom of God in a mystery, even the hidden wisdom, which God ordained before the world unto our glory: 


2:7. The message which Paul proclaimed was God’s secret wisdom, known only by God’s revelation (Matt. 11:25). At the heart of this wisdom is the plan of salvation intended for our glory, determined before time began (Eph. 1:4). 

Excerpt from: 
Walvoord, J. F., Zuck, R. B., & Dallas Theological Seminary. (1983-c1985). 
The Bible knowledge commentary : An Exposition of the Scriptures. 
Wheaton, IL: Victor Books.