My quick reflection on Genesis 6:5, “The LORD saw that the wickedness of man was great in the earth, and that every intention of the thoughts of his heart was only evil continually.” (ESV)
This is just before the Lord decides to flood the entire earth due to the wickedness on it. He saves Noah and His family out of the flood, only eight of the many thousands living on the earth.
There is no reason to think that this does not apply to all of mankind/humankind. The scope is verified in many other passages like Romans 3:10-18, 23. We also find the complete inability of all unsaved people to please God, Romans 8:8. These give us insight into unsaved man’s inability to please God in any way, by action or by thought.
Why is this? Fallen man suppresses the knowledge of God, Romans 1:18,21. Without the knowledge of God unsaved man is always motivated incorrectly in his/her actions. Instead of being motivated to glorify the one true and living God, the unsaved are motivated to glorify themselves or some other distortion, which is sin. So while feeding a hungry child may be good in itself and God is glad that the hungry child is fed, He is not pleased with the feeder unless he/she feeds to His glory, i.e. the feeder is saved and in the right frame of mind toward God.
It is very interesting to note the way Paul speaks about his mind, Romans 7:21-23,
So I find it to be a law that when I want to do right, evil lies close at hand. For I delight in the law of God, in my inner being, but I see in my members another law waging war against the law of my mind and making me captive to the law of sin that dwells in my members.
Paul sees another law which wages war against the law of his mind. And what does this law do? It makes him captive to the law of sin. So the law of his mind is the opposite of the law of sin – the law that wants to do right. This is the law of the mind, which is renewed by God in our sanctification, Romans 12:2. By the renewing of our minds through the Holy Spirit we are able to know/think and do good works. This is the first time we know of good works because it is the first time we can gauge what is good and what is evil by the only standard, which is God. As we draw closer to God, we are better able to discern good from evil. For we were saved to do the good works appointed to us by God, Ephesians 2:10 (see also v. 8-9).