'Understand' in the Bible

“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.”

Whoever is [spiritually] wise, let him understand these things;Whoever is [spiritually] discerning and understanding, let him know them.For the ways of the Lord are right,And the righteous will walk in them,But transgressors will stumble and fall in them.