There is nothing in this life that is hidden from God, he is all powerful, omniscient and omnipresent, and can make known or reveal to his children anything that they wish to know or discover, the Lord only tells us we must cry out to him in prayer and this way of responding and teaching us great things that are hidden and for this reason we cannot know.

King Nebuchadnezzar had a dream that disturbed him very much and wanted to know its interpretation and none of the wise men of Babylon could interpret it and the king decided to kill them all.

Daniel along with his companions cried out to God and the secret they cried out to God and the secret of that dream which was revealed, Daniel recognizing that both power and wisdom are from God, the only one who removes and places kings gives wisdom to the wise and science to connoisseurs. All of this happens because God is sovereign and is committed to responding to everyone who cries out to Him.

The word says that God will teach us great things unknown.
Because God has the power to reveal the deep as well as what is hidden for God, nothing is hidden. He knows the present, the past and the future. He also knows everything that is in darkness; because simply with God the light dwells and there is nothing that is brought to the light and remains hidden.

When we need God to reveal some matter or mystery to us, let us not doubt, we cry out to the God of Daniel who is the same as us.