'Mystery' in the Bible

He made known to us the mystery of His will, according to His kind intention which He purposed in Him

that by revelation there was made known to me the mystery, as I wrote before in brief.

By referring to this, when you read you can understand my insight into the mystery of Christ,

and to bring to light what is the administration of the mystery which for ages has been hidden in God who created all things;

This mystery is great; but I am speaking with reference to Christ and the church.

and pray on my behalf, that utterance may be given to me in the opening of my mouth, to make known with boldness the mystery of the gospel,