Just for fun, excerpts from two conservative Muslim fatwas (scholarly/legal opinions) about atheists.

Why an atheist being a good person does not make sense:

Whoever denies the Creator or refuses to worship Him, or joins others in worship with Him, deserves the most severe punishment, because for a man to deny his Creator, or refuse to worship Him, or join others in worship with Him, is the most serious of human sins, the most abhorrent of beliefs and the worst deviation. If a person is like this, there is no value in any good deed that he does. The atheist who does deeds that are good in his own eyes, and does whatever good deeds he can for his society, is like a man who kills his father and mother and takes good care of dogs. Does it not make sense that he should be punished and that his good treatment of dogs should not count for anything? The most important rights are the rights of Allaah, which are that He should be acknowledged and worshipped. The one who neglects this most important right will not benefit from anything he does with regard to people’s rights. Therefore if the atheist does not believe in Allaah and does not worship Allaah, there cannot be any good in the actions that he does for people’s benefit. But this atheist or mushrik who treats people well is still better than the atheist or mushrik who oppresses and mistreats people, and denies them their rights. He may be rewarded for his good deeds by being granted provision of food and drink in this world, but he will have no share in the Hereafter.

Why atheists are (possibly) not real:

Atheism, in modern terminology, means denying the Creator altogether, denying that He exists and not acknowledging Him, may He be glorified and exalted. The universe and everything in it, according to their claims, came about purely by chance. This is a strange view which is contrary to sound human nature, reason and logic, and is contrary to simple logic and indisputable facts. . .

Nevertheless, the atheist who denies the existence of Allah and rejects His Messengers and disbelieves in the Last Day, is in a greater state of kufr and his beliefs are more reprehensible than the one who believes in Allah and the Hereafter, but he associates something of His creation with Him. The former is stubborn and arrogant to an extent that can not be imagined or accepted by sound human nature. Such a person would transgress every sacred limit and fall into every sin; his worldview would be distorted to an inconceivable level. Yet many scholars who discussed the issue of atheism doubted that this has deep roots in the hearts of the atheists, and they affirmed that the atheist is only professing atheism outwardly; deep down he believes in one God.

There. That should settle things.