'Depths' in the Bible

But whoever shall occasion the fall of one of these little ones who believe in me, it would be better for him to have a millstone hung round his neck and to be drowned in the depths of the sea.

For us, however, God has drawn aside the veil through the teaching of the Spirit; for the Spirit searches everything, including the depths of the divine nature.

The fifth angel blew his trumpet; and I saw a Star which had fallen from Heaven to the earth; and to him was given the key of the depths of the bottomless pit,

and he opened the depths of the bottomless pit. And smoke came up out of the pit resembling the smoke of a vast furnace, so that the sun was darkened, and the air also, by reason of the smoke of the pit.