you took that out of context. every thought evil yes its said in noah's times. its like that now too cause end time Jesus says as in days of noah.
second point is Nehemiah was right, look:
Rom 2:14 For when the Gentiles, which have not the law, do by nature the things contained in the law, these, having not the law, are a law unto themselves:
i thought it was impossible to do any good ?
You're right..that's where it's coming from:
Genesis 6:5 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)
And, I don't think that any unsaved human is trying to do good now. They are idolaters and their lives don't revolve around a relationship with God. They cannot be good because their life doesn't revolve around God.
What does Romans 3 say about the state of all mankind?
You can't take Romans 2 and isolate it from Romans 3.
Romans 3:10-18 10 as it is written:
“None is righteous, no, not one;
11 no one understands;
no one seeks for God.
12 All have turned aside; together they have become worthless;
no one does good,
not even one.”
13 “Their throat is an open grave;
they use their tongues to deceive.”
“The venom of asps is under their lips.”
14 “Their mouth is full of curses and bitterness.”
15 “Their feet are swift to shed blood;
16 in their paths are ruin and misery,
17 and the way of peace they have not known.”
18 “There is no fear of God before their eyes.”
(ESV)
In Romans 2, it also says this:
Romans 2:12-16 12 For all who have sinned without the law will also perish without the law, and all who have sinned under the law will be judged by the law. 13 For it is not the hearers of the law who are righteous before God, but the doers of the law who will be justified. 14 For when Gentiles, who do not have the law, by nature do what the law requires, they are a law to themselves, even though they do not have the law. 15 They show that the work of the law is written on their hearts, while their conscience also bears witness, and their conflicting thoughts accuse or even excuse them 16 on that day when, according to my gospel, God judges the secrets of men by Christ Jesus.
(ESV)
Is any unbeliever doing good? Are there unbelievers who are trying to follow God's standards? I don't think so, given Romans 3.