1) First, when considering this position, it's important to recognize the difference between complexity and design. Complexity itself does not require an intelligent creator. It's easy to impose a design upon things that exist by chance or developed through a natural process like evolution.
To an extent, this argument gains traction because of wide misunderstanding of science and especially evolution. Everything in the universe conforms to certain simple scientific rules that have been repeated over billions of years. While this can be awe-inspiring, it by no means suggests a creator.
Failure to understand the scientific principles guiding the creation and development of the universe does not mean that a deity must exist to explain the natural world.
2) This argument presupposes its premise. People believe in scripture and place value in the words because they already believe in the religious principles the text describes. There is no inherent value to the Bible, Quran or any other religious text; these documents are not self-authenticating in any way.
In fact, many factual inaccuracies and inconsistencies can be found within religious texts themselves. For example, the Bible contains two separate creation stories, each of which provides a very different explanation. Similarly, there is no historical, archaeological or scientific evidence to support many of the stories in the Bible and the Quran.
Ultimately, religious texts are infinitely fallible because they are man-made products of whimsy, poetry, mythology and some history woven together into a new whole. The texts in the Bible have been gathered from many oral sources over thousands of years and compiled arbitrarily into a single document; it's hardly surprising that the narrative would be so inconsistent. Other religious texts have similarly convoluted histories.
Aside from the problems with individual texts, there's also the obvious issue that the very presence of multiple scriptures negates the authenticity of any single religious document. It's impossible for every religious book to be true; it's highly presumptuous to assume that one's own preferred scripture is the single "true" scripture while all the others are false accounts. It's far more likely that every religious book is equally fictitious and unreliable.
3) This argument is often offered as a last line of defense in religious debates, and the person posing it might feel very clever coming up with it. However, the premise of the argument is both flawed and ridiculous. The failure to disprove something does not constitute proof of its existence.
The burden of proof is always on the person making a claim, especially in cases where the claims are unsupported or unfalsifiable. With no enduring evidence that a God exists, there is simply no reason to believe in a deity, even if it's not possible to irrefutably disprove his existence.
Many thought experiments have been created to show the absurdity of these claims, such as the Invisible Pink Unicorn, Carl Sagan's "The Dragon in My Garage," Russell's Teapot or the Flying Spaghetti Monster. All of which are absurd claims without evidence and yet impossible to disprove. Familiarizing yourself with these thought experiments can give you a clear picture of exactly why the burden of proof should always be on the person making a claim.
4) The existence of Unicorns can not be disproven, therefore there are Unicorns.
Does that make sense to you? Nobody can disprove the existence of any mythical entity, that does not mean they exist. We determine things based on evidence. No evidence, no reality, no exitence. This frustrates the hell out of theists, but they know it is true and they would not take it on faith if I told someone that I had a Leprachaun in my closet. They would want to see it for themselves.
5) Just as miracles are impossible to prove without resorting to unreliable anecdotes, the power of prayer is certainly not supported by science. Belief in prayer relies on confirmation bias. Essentially, people remember the times that prayer seemed to "work" but conveniently forget the many occasions that they prayed and saw no response or received the opposite result of what they'd wanted. These unwanted results are often ignored completely or rationalized away.
Prayer is a type of magical thinking. Its appeal is undeniable; it feels empowering and makes individuals feel as though they have a measure of control over the world around them. But there is simply no evidence that prayers are anything more than a placebo. And unlike many placebos, prayer can actually be harmful.
The "power of prayer" is one of the most insidious and even harmful beliefs proffered by religion. When faced with any sort of tragedy or misfortune, prayer is one of the least helpful responses imaginable.
Prayer is like gambling when your prayer is answered you tell everyone when you are ignored you keep it a secret.
These are the main athiest points thank you.
