'Understand' in the Bible

I will not punish your daughters when they commit whoredom, nor your spouses when they commit adultery: for themselves are separated with whores, and they sacrifice with harlots: therefore the people that doth not understand shall fall.

“So let us know and become personally acquainted with Him; let us press on to know and understand fully the [greatness of the] Lord [to honor, heed, and deeply cherish Him].His appearing is prepared and is as certain as the dawn,And He will come to us [in salvation] like the [heavy] rain,Like the spring rain watering the earth.”

Who is wise, and he shall understand these things? prudent, and he shall know them? for the ways of the LORD are right, and the just shall walk in them: but the transgressors shall fall therein.