"Yet among the mature we do impart wisdom, although it is not a wisdom of this age or of the rulers of this age, who are doomed to pass away. But we impart a secret and hidden wisdom of God, which God decreed before the ages for our glory. None of the rulers of this age understood this, for if they had, they would not have crucified the Lord of glory." - 1 Corinthians 2:6-8 ESV
"For the mystery of lawlessness is already at work. Only he who now restrains it will do so until he is out of the way." - 2 Thessalonians 2:7a ESV
There is a mystery that transforms but there is also a mystery that corrupts. The mystery of iniquity involves the emotions. The emotions can get corrupted to the point where people form ideas that go against reason. We see that happening in the world. People betray friendships. They abandon marriages and children. They hurt themselves and others because of hate. It is a mystery. They unite in a hopeless cause against what is good and right and call evil good and good evil.
Then there is the mystery of love and transformation. It is the mystery of redemption. In truth it is the mystery of the resurrection. Christ's resurrection was the first domino to fall in a long string of dominoes. Yet this great coming alive is hidden and misunderstood.
People can live their lives baffled by both of these things. Apart from God there is no explanation.
When Christ is revealed then these mysteries begin to be revealed also. These things don't baffle us. We may not like what we see but we know enough about it to identify it as spiritual and not just natural.