None of the following comes from me. I found it at this site:
As an atheist, you will occasionally meet a non-atheist who wishes to argue against your belief system. If you are interested in discussing the matter, you may want to prepare yourself by learning these simple responses to common anti-atheist arguments.
The Bible says that atheism is wrong.
"The Bible also says some guy's donkey talked."
If you believe in God and are wrong, then it's no big deal, but if you don't believe in God and are wrong, you'll be punished eternally, so it's not a good idea to be an atheist.
"What if you're wrong that God prefers unthinking self-righteous toadies to honest people who try and live a good life?"
Deep down you really believe in God.
"Deep down, you really don't believe that."
You're only saying you're an atheist to rebel against authority.
"And if the Beatles grew long hair to rebel against authority, then they really had no hair -- is that what you're saying?"
You probably are an atheist because you had a bad experience as a child.
"You probably worship God because you hate your real father."
There are no atheists in foxholes.
"Probably because we have less excuses to start wars."
If you don't believe in God, you'll go to Hell!
"If you don't stop believing in God right now, I'll punch you in the face."
Why are you mad at God?
"Because he's supposed to be all good but he doesn't even have the common decency to exist."
Atheists are Satanic.
"Just like theists are agnostic?"
Without God there is no morality.
"Are we talking about the God that ordered Moses to kill babies and asked people to set animals on fire because he liked the smell?"
God is perfect, and He couldn't be perfect if He didn't exist, which proves that He exists.
"No, it just proves he isn't perfect."
People who follow Jesus are good, so you should follow Jesus.
"Chemotherapy can cure cancer, so everyone should have chemotherapy."
Jesus was either a liar, a crazy person, or the son of God. He spoke against liars, and his behavior wasn't crazy, so the only remaining possibility is that he was the son of God.
"So you're telling me that if a polite, honest-looking, well-spoken, nicely dressed man walked up to you on the street and introduced himself as the earthly incarnation of God, you'd figure he probably is? Have you considered the possibility that you're the one who is crazy?"
There were eye witnesses that Jesus worked miracles.
"There are eye witnesses that Bigfoot exists, Uri Geller works miracles, and aliens abduct people."
Most people who know about Jesus believe in Him.
"If most people jumped off a bridge..."
I know from personal experience that God exists.
"No he doesn't. He told me so himself."
God wants you to believe in him without rational proof.
"Then he's certainly doing a fine job of not tempting me with evidence."
You say you don't believe that God exists, but the word "God" is meaningless if there is no such thing, so you are admitting that God exists even as you deny his existence.
"That reminds me, I don't believe you owe me $100."
Hitler was an atheist.
"I don't know about Hitler's religion, but I do know that he was heterosexual, so can I assume you're against that, too?"
Einstein believed in God. Do you think you're smarter than Einstein?
"If he believed in God, yes."
The founding fathers intended the United States to be a Christian nation. Atheists aren't welcome.
"Are you sticking with the whole 'slavery' thing, too?"
The universe is so complex that someone must have designed it.
"I don't know -- that sentence was fairly complex but there was obviously not much thought behind it."
Atheists believe in evolution, but if we teach our children evolution in public school they will believe that they are no better than animals and will grow up immoral.
"I've met public school children. Most of them aren't any better than animals."
Evolution violates the second law of thermodynamics.
"No, but God does."
Well, evolution's only a theory.
"So's your old man."
How can you not believe in Jesus Christ when the evidence is overwhelming?
"Well, Jesus's divinity is only a theory."
There's proof that God exists, like the Bible and miracles.
"If your twenty-year-old son still believes in Santa Claus because he read a book about Santa visiting and presents magically appeared on Christmas morning when he was a child, would you praise him for having faith in the face of overwhelming evidence or call him an idiot?"
My parents raised me to believe in God. Are you calling my parents liars?
"Can we talk about the Tooth Fairy for a minute?"
There are so many wonderful things in the world, how can you say there is no God?
"It's really pretty easy: 'There is no god.' See?"
There is so much beauty in the world that only God could have created it.
"My wife's beautiful, and my mother-in-law made her."
If there is no Heaven, then where do you go when you die?
"The same place you were before you were conceived, I assume."
You can't prove God doesn't exist.
You don't know everything.
You can't see air, but you believe in it.
"I can't see ignorance, but I can smell it. Right now, in fact."
You can't see love, but you believe in it.
"And I agree that god, like love, is just a concept."
God made His image appear in this tortilla!
You call yourself an atheist but you have faith. Everyone has faith in something.
"I have faith that this conversation isn't going anywhere. Bye!"