John Calvin's quote as displayed in this entry is really right about how Christians can lose guidance of the Holy Spirit if they rely on their own intelligence. How does a Christian go wrong with his or her spiritual life but to rely confidence in their own intelligence rather than the Spirit. Proverbs 3:5-6 gives this instruction saying, "Trust in the Lord with all thine heart; and lean not unto thine own understanding. In all thy ways acknowledge him, and he shall direct thy paths."
The King James Study Bible says this wonderful quote on Proverbs 3:5-6, "Three commands are given: trust meaning "rely on, depend on"; lean not, meaning do not depend on your own native instincts; and acknowledge Him meaning have fellowship and intimacy with God in all of life. The result of such devotion is that God will make the paths straight before you." Depending on one's own knowledge and intelligence is a real pitfall because all people are sinners. Even if Christians are no longer living their old life but they still have to fight against sin. The only real power against sin is by the grace of God (Titus 2:11-14) and not the ability of the human flesh.
It is true that Christians should gain knowledge, it's an asset and an advantage to have intelligence but it's stupid to discredit who allowed that intelligence and knowledge. When King Solomon asked for wisdom to govern the people well, he did govern the people well. When he started to rely on his own wisdom than God, that's when he made a fool out of himself. Knowing how he started out a revival, it ended in ruin because he had several unequal yokes. Nehemiah 13:16 says, "Did not Solomon king of Israel sin by these things? Yet among many nations there was no king like him who was beloved of his God and God made him king over all Israel; nevertheless did outlandish women cause to sin."
In Ecclesiastes 2:16 we hear King Solomon say, "For there is no remembrance of the wise more than of the fool for ever; seeing that which now is in the days to come shall all be forgotten. And how dieth the wise man? As the fool." He saw himself as a huge fool with all he did especially when he took 998 more idolatrous women (the first one being the daughter of an Egyptian king) into his harem. He had a loving Shullamite in the Song of Solomon but he foolishly made idolatrous alliances. The fact he was a saved man caused him to have genuine godly repentance of his backsliding and turned back to God near the end of his life.