It's not enough to "know" things, you also have to put them together. Understanding in Scripture is directed toward discerning good from evil; truth from falsehood. In other words, the man who has understanding has good judgment. He comprehends the right relationship of the particular pieces of knowledge to the whole. The Bible describes the sons of Issachar as men "who had understanding of the times, to know what Israel ought to do" (1 Chron. 12:32). Do you have a truly biblical understanding of politics and culture? Do you know what you and others should be doing? Or are you relying on the media and your own thoughts to navigate through your life?
While the unbeliever swerves into the truth on a regular basis, without the fear of the Lord he has no means of discerning good from evil (Heb. 5:14). He is a creature, made in God's image, living in God's world. However, since he does not acknowledge any of this, the truths he does pick up fall short of accomplishing their intended purpose which is to glorify God. We have to know why and how things fit together so that we don't muddle our way through life. We need a coherent worldview that is comprehensive. Without this, we cannot make sense of our own lives, or the world around us, much less the things of eternity.
Do you understand the covenantal structure of all of life and what the Bible teaches about how life works? Blessings and curses? Visible and invisible? King Solomon prayed, "So give Thy servant an understanding heart to judge Thy people to discern between good and evil" (1 Kings 3:9). Job observes, "And to depart from evil is understanding" (28:28).
Genuine understanding is evidenced in obedience to the truth as we see in these passages from Psalms: "A good understanding have all those who do His Commandments" (111: 10); "Give me understanding, that I may observe Thy law, and keep it with all my heart" (119:34); "Give me understanding, that I may learn Thy commandments" (119:73); "From Thy precepts I get understanding; therefore I hate every false way" (119:104). The Proverbs observe: "a man of understanding walks straight" (15:21)."The rich man is wise in his own eyes, but the poor who has understanding sees through him" (28:11).
God complains to Jeremiah, "For My people are foolish. They know Me not; they are stupid children, and they have no understanding. They are shrewd to do evil, but to do good they do not know" (4:22). Daniel and his companions were described as those who were "endowed with understanding, and discerning knowledge" (Dan. 1:4). The apostle John points us to the ultimate purpose of understanding when he writes, "And we know that the Son of God has come, and has given us understanding, in order that we might know Him who is true..." (1 John 5:20).