What is "The Knowledge of Man?"
It is what issues forth from knowing God rightly (from what the Bible calls, "The Knowledge of God"). The knowledge of man is the ability to see ourselves rightly in the light of who God is; it is rightly seeing of oneself, from God's perspective. The reality is this: We can't truly know ourselves apart from God.
"Without knowledge of God there is no knowledge of self...Without knowledge of self there is no knowledge of God... But though the knowledge of God and the knowledge of ourselves are bound together by a mutual tie, due arrangement requires that we treat of the former in the first place, and then descend to the latter." - John Calvin
"The knowledge of God and the knowledge of self always go hand in hand. We see ourselves differently because we have seen God as He is. And we understand our calling, to reflect God as Christ did, in a new way." - Jen Wilkins
Passages On The Knowledge Of Man
“But we are all like an unclean thing, And all our righteousnesses are like filthy rags; We all fade as a leaf, and our iniquities, like the wind, have taken us away. And there is no one who calls on Your name, who stirs himself up to take hold of You…” - Isaiah 64:6-7a NKJV
“The heart is deceitful above all things, And desperately wicked; Who can know it? I, the Lord, search the heart, I test the mind, Even to give every man according to his ways, According to the fruit of his doings.” - Jeremiah 17:9-10 NKJV & “The heart is hopelessly dark and deceitful, a puzzle that no one can figure out. But I, God, search the heart and examine the mind. I get to the heart of the human. I get to the root of things. I treat them as they really are, not as they pretend to be.” - Jeremiah 17:9-10 MSG
You search the Scriptures, for in them you think you have eternal life; and these are they which testify of Me. But you are not willing to come to Me that you may have life. “I do not receive honor from men. But I know you, that you do not have the love of God in you. I have come in My Father’s name, and you do not receive Me; if another comes in his own name, him you will receive. How can you believe, who receive honor from one another, and do not seek the honor that comes from the only God? - John 5:39-44 NKJV
Here are Some Passages Where Man Thinks He is Doing the Right Thing and God/Jesus Sees Right Through It:
Right after the cleansing of the Temple > “Now when he was in Jerusalem at the Passover Feast, many believed in his name when they saw the signs that he was doing. But Jesus on his part did not entrust himself to them, because he knew all people and needed no one to bear witness about man, for he himself knew what was in man.” - John 2:23-25 ESV
Right after the feeding of the 5,000 preceded this encounter > “When the people saw the sign that he had done, they said, “This is indeed the Prophet who is to come into the world!” Perceiving then that they were about to come and take him by force to make him king, Jesus withdrew again to the mountain by himself.” - John 6:14-15 ESV
A little after the feeding of the 5,000 preceded this encounter > “When they found him on the other side of the sea, they said to him, “Rabbi, when did you come here?” Jesus answered them, “Truly, truly, I say to you, you are seeking me, not because you saw signs, but because you ate your fill of the loaves. Do not work for the food that perishes, but for the food that endures to eternal life, which the Son of Man will give to you. For on him God the Father has set his seal.” Then they said to him, “What must we do, to be doing the works of God?” Jesus answered them, “This is the work of God, that you believe in him whom he has sent.” - John 6:25-29 ESV