Trying to breakdown and list refutations of both common and modern arguments for a spiritual life, god belief, prayer or religious theology is easy. Attempting to find the top salient arguments is hard. Not because there aren’t enough to refute believers, but because there are just so many really good arguments against the supernatural and god belief.
The list is an amalgamation from the Atheist Debater and a confluence of writings from Hitchens, Dennett, Harris and Dawkins, et all:
1. Evolution v. the Bible (v. ID): It is important to understand the process of evolution not only because of the practical reasons such as health, medicine and educational purposes. It is the answer to where we came from. There is no need or evidence for a designer, intelligent or otherwise, to make evolution and natural selection occur
2. Your god brings you happiness: The real events in one’s life gives it meaning and purpose. Choosing to place a personal god as a filter or context to give your life meaning is a personal decision. It is a free choice and not one shared with or by everyone
3. God belief and morality: If belief in god is the sole reason why you don’t do bad things, then you should meet people who live and love, have moral lives and don’t believe in god. They are proof that godless people can be just
4. America was founded on Christian principles: Just read the First Amendment to see this is untrue. Many of country’s founding fathers were Deists, not Christians. Including Thomas Jefferson, Benjamin Franklin, James Monroe, James Madison, John Adams and Thomas Paine. Jefferson removed all of Jesus’ supernatural events from his “Jeffersonian Bible” and Paine wrote, “The Age of Reason” a scathing critique of the Bible
5. Miracles: Miracles are violations of natural laws. If miracles occurred before, why do they not occur in our lifetime? The only answer is they cannot occur therefore they are all false
6. Growth of Humanism/Atheism: The number of people who are spiritual or believe in religion is shrinking world-wide as science show us the natural mechanics of the universe. Internationally, atheists and non believers are over one billion strong and growing
7. Remember the fallacy of Pascal’s wager which is to essentially believe just in case there is a heaven and hell: A refutation is here: Christians pray to Jesus=Avoid Hell; Muslims pray to Jesus=Go to hell; Jews pray to Jesus=waste of time. What do you do? Which religion is correct? None. How about then just being a good person and enjoy your life?
8. First Cause Argument: Science shows us the nature of the world and universe. It doesn’t require god. If nothing can exist, who created god?
9. Repentance: Repentance is a cop-out. Christianity allows for the forgiveness of any crime if you accept Jesus and repent. Humanity was born immoral and sinful. Without Christ or Allah or Yahweh you are dammed in some way. All religions tell you to get in line or be rejected. Why not just do good deeds for others as their own honorable acts
10. One cannot prove a negative: If one cannot prove god doesn’t exist, he must or may exist. But the actual burden is on the believer to prove god’s existence, not on the non-believer to show god doesn’t exist. We can already prove there is no god as there is no evidence (natural or supernatural) for god
11. Religion is the basis for morality: Religion kills and causes unjust suffering, historically we have numerous "Holy Wars", the Crusades and the Inquisition. In modern times we have the attacks of 9/11, and the ongoing violence against women, ethnic minorities, other religions and against scientists, intellectuals and non-believers
12. The afterlife: There is no evidence of an afterlife, therefore the afterlife is not real. Neither is resurrection, god(s), ghosts, souls, mind readers, fortune telling, witches or any supernatural occurrence that cannot be tested by science
13. Atheism is a replacement for religion: Atheism is not a religion. Atheism rejects belief in religion and deities. Atheism says nothing about morality, ethics or values. Atheism is not moral or immoral
Ultimately remember two important aspects of the Humanist and atheist worldviews so that we can have and sustain political and social impact on our nation and the world. First, we have to accept what Carl Sagan said so elegantly, “Extraordinary proof requires extraordinary evidence.” Secondly, as Sam Harris notes, the only way to create a viable global civilization is to do so without religion or god belief.
Theology, religious philosophy and religious ritual are not benign by their very nature and as such are part of the problem, not the solution. They are exclusionary and antithetical to any one-world possibility. It is only through humanistic atheism that we may reach any universal understanding and social justice.