Straw man! I never said anyone who doesn't believe in God must believe rape, murder, and incest are okay. Never said that. I said that they can NOT say conclusively with any authority that those things are wrong. They just can't. Without a higher power, an absolutely objective authority, these things become just matters of opinion. Without said authority you can never prove those things are wrong no matter how hard you try. We have seen in the varying civilizations of history varying values and ideas of morality. Those things can change with society. It is not set in stone without a higher power. And...not sure what was meant by your last sentence, but I will try to expound on it. Yes Muhammad salla allahu alihi wa salaam, was the final messenger of God. The ahadith are not equal in authority with the Qur'an which is the eternal word of Allah. It is however a part of the sunna and example of the Prophet (pbuh).