But let's for a moment say that atheism isn't just the 'lack of belief in gods' default. Let's say for a moment that atheism *is* the belief that there are no gods or goddesses. And let's also say that an atheist comes to this position through consideration of theistic claims. We'll call this person a 'considered atheist'.
Does having the belief that there are no gods or goddesses *really* take as much faith as believing there are gods and goddesses?
This is a hard question to answer in one way because faith is not really measurable. I'm not sure if there's a way to quantify it. I don't know what units of measurement one uses to work out how much faith a person has. Gullibles? Deludeds? Who knows? So let's just assume you can measure faith...somehow.
THE BELIEF IN GODS AND GODDESSES:
The overwhelming majority of theists are so because they were indoctrinated as children. They aren't just told to believe, they're told a god exists with the same authority and conviction that they're told the sky is blue, that water will make you wet, and that something hot may burn you. They're not presented with faith as an alternative to reason. They're not presented different faiths and allowed to choose which of them they think makes the most sense. They are told that the god their parents believe in is real, he (most likely) watches everything they do, and if they aren't saved, they'll burn in hell forever. (Obviously there's variations on this theme but I think this is basically how it is for a very high percentage of believers).
Actually, let me clarify - Children (infants) are not told this god is real directly. It's never 'God is real and therefore you must believe in him'. It's more like 'if you steal, God will see and you'll go to hell'. It's just taken for granted that their god exists. Non-existence is not a question. The possibility of their god not existing is never even raised. It's never considered.
By the time these people reach the age of reason they are so fully convinced that their god is real and that their version of theology is real, that it's no longer a case of there being other possibilities to think about, it's that they are right and everyone who doesn't agree with them is wrong, and those people will, in a majority of cases, end up burning in hell forever.
It gets to the point where many believers will have the interesting position of both having faith that their god is real and 'knowing' that their god is real. Some of these people know it to such a degree that they will die or kill for this god.
It would take an incredible amount of faith in a deity to end a life, yours or someone else's. But even if we don't take it to that extreme there's still a lot of faith involved. In order to be a follower of today's big religions one must accept that all kinds of nonsense happened in the past. One must believe things that if they were told happened today most would have no chance of believing and they must believe these things with no evidence at all - except scripture.
Scripture - the stories written by ancient people who didn't know how to investigate any kind of natural phenomena to find out what was actually happening. They not only didn't know how to, they didn't know they could. Before people developed methods for properly investigating how things happened and how things worked they thought epilepsy was demons possessing someone. They thought lightning was the wrath of a god. They thought a solar eclipse needed human sacrifice. They thought a story of a burning bush being the medium through which a god speaks was believable.
Believers today hear these stories and think them real. Modern day believers not only have no evidence to support these stories but they fail to consider that these stories were made up by people who didn't know better. They fail to consider that these stories were made up by people whose understanding of the universe wouldn't let them pass a 5th grade test. That's not to say they were stupid people. They just didn't know what we know today.
So with nothing to go on but the scripture of their religion and the say so of parents, priests and peers, these people believe without reservation, and without any confirmation that any gods exists at all let alone the god they happen to believe in, that their god is real. The evidence they provide is all fallacious. I haven't seen a new argument for the existence for god in a very long time. They always fall at either personal incredulity (argument from ignorance), special pleading, or they argue from personal revelation, which is, of course, not enough to convince anyone else of anything.
So the conclusion on belief in gods and goddesses it is 100% faith, with no redeeming logical reasoning - at all.
THE BELIEF THAT NO GODS AND GODDESSES EXIST
As I said at the start, the majority of atheists will tell you that atheism is NOT the belief that no gods or goddesses exist, but it's lacking any belief that they do. Let's for a moment though throw out this notion of absolute certainty. Let's say that declaring no gods or goddesses exist is the equivalent of declaring no unicorns exist. Can one be absolutely certain that no unicorns exist? No, I don't think so. But is it outrageous to say 'I believe no unicorns exist'? No, it's really not.
So if someone came out and said 'I believe no gods or goddesses exist' what are they really saying? I think they're saying something like 'The idea that any of the claims I've heard for the existence of gods or goddesses are real is so unlikely that they can all be dismissed'.
To believe in God (as the big two religions think of him) we must accept that he is the supernatural being who created the entire universe, put life on one of eight planets, in a solar system around one of hundreds of billions of stars in one of hundreds of billions of galaxies.
He apparently cares about what we wear on our heads, whether or not the boys keep their foreskins, and has all manner of seemingly nonsense rules and demands. The kinds of rules and demands we'd expect ancient superstitious people to put in their rule book.
He rules this one planet but allows all kinds of evil, including the starvation, rape, and killing of children, yet his believers claim he loves us all. According to some he populated the planet and then wiped it all out because the people he created were wicked. And this was part of his plan.
The stories associated with gods and goddesses are simply ridiculous. They are pure nonsense and it is hard to imagine a scientifically literate, well educated, adult believing them if they'd never heard them before the age of reason.
Stories from the bible sound like exactly what they are - Fantasy from ancient, superstitious people who didn't know better. We know Adam and Eve never existed, evolution shows us that. No Adam and Eve, no fall of man, no fall of man, no need for saving, no need for saving, no need for Jesus. The stories are fabricated. To dismiss the claims that gods and goddesses exist based on the stories about them alone seems quite reasonable. Add to this that gods and goddesses have all been invented by people who didn't have the scientific method of investigation and analysis at their disposal and the likelihood of gods and goddesses being real pretty much vanishes into oblivion.
Then there's the answers we have versus the answers ancient people supposed. For example they used to think lightning was the work of a god throwing it across the sky. We now know it's not. It's natural and easily explained. For anything for which there is an answer, where the claim was previously 'god did it' - we now know no gods or goddesses were required. Not at all. Not once.
There is no evidence to support the existence of supernatural beings, but there is evidence to suggest they are simply the products of human imagination. Therefore to believe they don't exist seems quite reasonable.
But this is not a case against the existence of gods and goddesses as such, this is a discussion about the faith required to believe one way or the other.
So on the one hand we've got believing in the existence of a being never proved. A being (or beings) who has been shown to exist nowhere but in ancient superstition and the gaps in knowledge of modern day believers. This belief is 100% faith based and, as demonstrated in the above, has no valid reason for thinking it real.
On the other hand we've got believing that the superstitious beliefs of ancient people aren't real. Belief that saying 'I don't know, therefore god' is *not* a valid argument. This belief comes with reasoning - No gods have ever been the verified cause of anything and all the people who invented gods did so in times and places where they weren't in the habit of investigating actual answers. This is a considered position. A position derived from analysing the claims gods and goddesses exist and applying logic and common sense. One does not need much faith, as such, to hold this belief.
Let me end with an example. Imagine you're at home and the phone rings. A fellow house member answers it and says it's for you - and it is capital G God.
God has never been proven to ring people up, just as he's never been proven to create universes or do any of the things attributed to him.
So when your house mate tells you it's God on the phone does it take just as much faith to believe it's not god as it would to believe it is?
Of course not.