When the woman saw that the tree was good for food, and that it was a delight to the eyes, and that the tree was desirable to make one wise, she took from its fruit and ate; and she gave also to her husband with her, and he ate. Then the eyes of both of them were opened, and they knew that they were naked; and they sewed fig leaves together and made themselves loin coverings (Genesis 3:6-7 NASB). .
For years now, rightly or wrongly, I've linked the above verses to the apostle John's description of
. . . all that is in the world . . ..
The "pride of life" is but one element of "all that is in the world." The other two elements are "the lust of the eyes" and "the lust of the flesh."
But what is "the world"? Biblically, the world (cosmos) is an organized and orderly system--a kingdom, if you will--having its roots in rebellion against God. Jesus said to Pilate,
“My kingdom is not of this world. If My kingdom were of this world, then My servants would be fighting so that I would not be handed over to the Jews; but as it is, My kingdom is not [l]of this realm” (John 18:36 NASB, my emphasis).
Notice the contrast Jesus makes in his interaction with Pilate. There are two kingdoms, Jesus asserts. There is a kingdom of this world, and there is a kingdom Jesus calls "my kingdom."
From Genesis to Revelation, those two kingdoms are in conflict: the kingdom of darkness and the kingdom of light; the kingdom which is under the temporary control of God's arch enemy, Satan; and the kingdom of heaven (or Kingdom of God), which is an eternal kingdom under the ultimate authority, God Himself. From G. F. Handel's Messiah come the following words, which are based upon Revelation 11:15:
The kingdom of this world;
The kingdom of our Lord
And of His Christ
And He shall reign for ever and ever . . ..
Until that time when “the kingdom of this world” becomes “the kingdom of our Lord and of his Christ,” the two kingdoms will be in opposition with one another. Satan and his minions, armed with “the lust of the flesh, the lust of the eyes, and the pride of life,” will be in perpetual conflict with God and his angels, and with his image bearers on earth, but particularly with the children of God, who comprise a kingdom of priests unto their God (Exodus 19:6; Revelation 1:6 and 5:10).
We gain insight into how Satan opposes God and his kingdom by parsing the interaction between the serpent and Eve in the Garden of Eden, an excerpt of which begins this answer. Notice the writer of these words gives us a template for all that is in the world:
the lust of the flesh . . . (corresponds to) . . . "the tree was good for food”
the lust of the eyes . . . (corresponds to) . . . “the tree was a delight to the eyes”
the pride of life . . . . . . . (corresponds to) . . .“the tree was desirable to make one wise"
God gave to Adam one prohibition and one only, and we assume he relayed God's prohibition to his “helpmeet.”
The LORD God commanded the man, saying, “From any tree of the garden you may eat freely; but from the tree of the knowledge of good and evil you shall not eat, for in the day that you eat from it you will surely die (Genesis 2:16-17 NASBU).
Put simply, the "pride of life" is an autonymous life, a life lived in opposition to God and his command, which in Eve's case was partaking of the fruit of the tree of the knowledge of good and evil.
Not without blame, Adam, who was with Eve at some point in the temptation, also disobeyed God's prohibition and ate of the fruit. Each person was culpable before holy God, though Adam's culpability was worse, since he failed not only to keep God's command, but he also failed in being the head of the woman whom God had graciously given to him (see Romans 5:12-21, where the apostle Paul puts the blame squarely on Adam, not his helpmeet).
In conclusion, at the heart of the pride of life is the illusion that “my way is the right way, so forget God.” The pride of life originates in a lie, a lie that says God's image bearers have the right to live autonymous lives, making their own way through life without reference to God. Proverbs, however, exposes that lie, telling us at least twice:
There is a way which seemeth right unto a man, but the end thereof are the ways of death (14:12; 16:25 KJV).
The truly wise person, instead of pridefully "leaning on his or her own understanding" (Proverbs 3:5) accedes to God's sovereign right to direct their path through life. Refusing to be wise in their own eyes (Proverbs 3:7), they humbly submit to God's will, knowing with great assurance that in the end, God will raise them up (1 Peter 5:6).