Be not wise in thine own eyes: fear the Lord, and depart from evil.
When we think we are wise and become prideful, we will fall into evil.
The book of Proverbs invites us to set our eyes on and trust in the Lord. Verses 5 and 6 of the same chapter today calls us to fix our hearts on God, to trust Him completely, and to recognize Him as the Guide of our path.
But the opposite of trusting God is thinking ourselves wise. Although it is true that there are wise men and women in the world, the beginning of their fall is when they begin to believe themselves wise. We must recognize that all we are (if anything we are) is because of the grace of our God.
It is for this very reason that the Proverbist urges us not to be proud but to fear the Lord. Fear is having a correct perspective of who God is and who I am in light of my God. If I see God for how great He is, I will be inclined to look to Him for wisdom and guidance.
On the other hand, if my interest is in finding my own path based on my own wisdom, then instead of being able to turn away from evil, I will only fall into it. Look at it this way. A trust and focus on the One Who is holy leads me to imitate Him. Trusting and focusing on someone who is a sinner (in myself) only leads me to the sin that my sinful being loves.
Who are you focused on today? God wants you to focus on Him to protect yourself from your own bad decisions that lead to sin. When we think we are wise and become prideful, we will certainly fall into evil.