'Secret' in the Bible

the secret that hath been hid from the ages and from the generations, but now was manifested to his saints,

to whom God did will to make known what is the riches of the glory of this secret among the nations -- which is Christ in you, the hope of the glory,

that their hearts may be comforted, being united in love, and to all riches of the full assurance of the understanding, to the full knowledge of the secret of the God and Father, and of the Christ,

praying at the same time also for us, that God may open to us a door for the word, to speak the secret of the Christ, because of which also I have been bound,