'Mystery of God' in the Bible

that their hearts may be comforted, firmly united together in love, and unto all riches of full assurance of understanding, in the knowledge of the mystery of God, and of the Father, and of Christ;

And confessedly great is the mystery of godliness: God was manifested in the flesh, justified by the Spirit, seen of angels, preached among the Gentiles, believed on in the world, received up into glory.

but that in the days of the blast of the seventh angel, when he shall sound, then shall the mystery of God be completed, as he spake by his own servants the prophets.