'Hidden' in the Bible

on that day when, as my gospel proclaims, God will judge the secrets [all the hidden thoughts and concealed sins] of men through Christ Jesus.

"Their throats resemble an opened grave; with their tongues they have been talking deceitfully." "The venom of vipers lies hidden behind their lips."

I do not want you, believers, to be unaware of this mystery [God’s previously hidden plan]—so that you will not be wise in your own opinion—that a partial hardening has [temporarily] happened to Israel [to last] until the full number of the Gentiles has come in;

Now to the one who is able to strengthen you with my gospel and the message that I preach about Jesus, the Messiah, by revealing the secret that was kept hidden from long ago