Given this view that it is personal and benign, a question might arise, "Does it matter?" Or, "What's it to the atheist what I believe or not?", Or, "What harm is it doing?". Or, "Given all the good that religion does, provided it's a benign religion that isn't 'fundamentalist', doesn't do harm, what's the problem?"
For me it's the truth that matters, and the only route to truth we have as far as I can tell is reason and the evidence of science.
One problem as I see it for any benign faith is that it's a mix of reason, evidence and faith. The reason helps such a believer to dismiss all the nasty and down right obvious crazy stuff, but it stops short with the basic belief in a God of some sort. To give up on reason and evidence at that point seems to have negated much of the benefit put in it up front. But it's not always obvious where the reason ends and the faith begins. The reason melds seamlessly into confusion as religious reasons merges into obscure religious language.
Confusion and obfuscation are arguably the best way to go. Obfuscation is legal, it's easy, there's always an abundant supply and it often does the trick. The more unclear it is exactly what one is arguing, the more trouble one's opponents will have in refuting one's claims. 
It's also arguable that obfuscation is what postmodernism is all about. Clouds of squid ink in the form of jargon, mathematical equations whose relevance is obscure, peacock displays of name-dropping, misappropriation and misapplication of scientific theories are often seen as postmodernist 'discourse'. Nietzsche, Heidegger, Heisenberg, Einstein, Gödel, Wittgenstein are hauled in and cited as saying things they didn't say - sometimes as saying exactly the opposite of what they said. ... The tactic doesn't work with people who actually know something of Einstein, Heisenberg or Gödel - but what of it? How many people is that? And it does work with many who don't. 
I'm not out to criticise the ignorant simply for being ignorant. None of us has the capacity to know all that has been discovered - we may be limited by time, access, interest or intelligence. The problem is that those making great claims for their world view that use these references should really check with those that have a better understanding before jumping straight in and acquiring this knowledge in the construction of their pseudo-knowledge.
The confusion of course raises it's own questions for the believers.
Asking unanswerable questions is an inconclusive but useful tactic. ... "But why did all this happen? Why is there something rather than nothing? Why is there Mind? Why is there order? ... The fact that no one can answer such questions is taken by the pure of heart and limpid of mind to entail divine explanation. The fact that such explanation allows the questions to be asked all over again seems not to trouble the divinely inclined. 
i.e. God answers nothing.
Of course if the questions are allowed to continue, the contortions of explanation become greater and greater, more obscure language is employed. It is more important that the faith is maintained, at the expense of clarity and reason.
In fact, the contortions are a giveaway not only that the explanation is not the right one, but that something is badly wrong with the method of generating the explanation, that things are back to front, that the enquirer has started, not with a desire to produce an explanation, but with the desire to produce a particular explanation, or a particular kind of explanation. 
What is necessary to get at truth?
What should trump what? Should rational enquiry, sound evidence, norms of accuracy, logical inference trump human needs, desires, fears, hopes? Or should our wishes and beliefs, politics and morality, dreams and visions be allowed to shape our decisions about what constitutes good evidence, what criteria determine whether an explanation is supported by evidence or not, what is admissible and what isn't? 
How much do we want the truth?
The truth is important to us, but so are our needs and desires and hopes and fears. Without them we wouldn't even recognise ourselves. Without them, we think, we would merely be something like an adding machine. An adding machine can get at the truth, given the right input, but it doesn't care. We want the truth but we also want to care - wanting the truth is indeed inseparable from caring. We want it, we care about it, it matters, and so do various other things we want and care about, some of which are threatened by the truth. ... But we have to choose. ... If we've never bothered to decide that truth matters, and that it shouldn't be subject to our wishes - that, in short, wishful thinking is bad thinking - then we are likely to be far less aware of the tension. We simply allow ourselves, without much worry or reflection, to assume that the way humans want the world to be is the way the world is, more or less by definition - and endemic confusion and muddle is the result. 
The muddle and confusion is so obvious in the Alice in Wonderland nonsense of much religious language - the desire to believe in the impossible (or at least un-evidenced) things manufactures incomprehensible language about incomprehensible beings, agents that interact yet don't exist, that we can't know of yet we know what they want from us.
Religion and related modes of thinking such as New Age, Wicca, paganism, the vaguely named 'spirituality', are where this outcome is most obvious. Public discourse features talk of God-shaped holes, of a deep human need for 'faith', of the longing of transcendence, of the despair and cosmic loneliness that results when God is doubted, and the like ... without apparently stopping to notice that there may be reasons to prefer true beliefs rather than false ones. 
What reasons? There are many. One is truth is something of an all-or-nothing proposition. It is intimately related to concepts such as consistency, thoroughness, universal applicability, and the like. If one decides that truth doesn't matter in one area what is to prevent one deciding it doesn't matter in any, in all? 
It's surely the nature of truth that it has to be all of a piece. It's norms have to apply here as well as there, if they are to apply at all. That is why relativism about truth is always self-undermining. If we say, 'there is no truth, truth is an illusion, a myth, a construct, a mystification' then that statement is not true - so there is truth then. 
Does it matter that we kid ourselves?
Our internal private thoughts might not matter at all. ... But how we influence each other, how we teach - by writing, by journalism, by talking on the radio, on platforms, in churches, in mosques, in classrooms - it does matter. If we are going to influence people, it's important we get it right. 
This is crucial as far as I can see. There's enough fog, lack of clarity, confusion, in transcribing thoughts from one mind to another as it is. The last thing we need is the obfuscation of falsehoods. But it doesn't have to be lies. There doesn't need to be intentional dishonestly. The transmission of unsupported ideas, non-truths, non-facts, sold as truths, or alternative truths is an easily acquired skill.
It might seem like there are good reasons to hide from truth. When it's trivial, when it's short term, then maybe we can excuse it. It might be a useful coping mechanism that allows us to avert pain, to concentrate on work, to withdraw from anger. But this isn't to deny the truth, it's just to postpone it, compartmentalise it, to push attention to one side. But this shouldn't become the rule, if we want to avoid living outside of reality. Truth isn't subject to our whims, our wishful thinking. But it's possible to live that way if we get into the habit.
If we minimize true facts that we dislike too often, we may lose sight of the fact that it is our reaction and degree of attention that is subject to our wills, and start to think that the facts themselves are subject to our wills. But on the whole they're not. 
Religious scholarship, theology, seems to me to be worst of the search for the answers. What kind of search for truth is it, when the truth is declared before the search begins, when search is directed at affirming what is already believed to be the truth? This isn't the discovery of truth; it's rationalising away the evidence to affirm the truth. Religion is often explained as a journey of discovery. This is the poorest form of journey of discovery; it's a journey through the front door that ends on the doorstep, where the 'truth' is already packaged up neatly into a three letter word, God. The only remaining work to do is to go back inside and rationalise about how this might be, or what it might mean, or how it can be applied to persuade people to conform to it. No evidence is required; in fact evidence has been a nuisance for religion from the start. As soon as someone asked, "How do you know that?", religion was on the defensive.
Religion is a big part of our lives, even if we are non-believers, because it is so ingrained in our history. But religion is supposed to be an honest affair isn't it? Don't we have enough to contend with?
There are fields where indifference to truth is no handicap - advertising, PR, fashion, lobbying, marketing, entertainment. In fact there are whole large, well paid, high status areas of the economy where truth-scepticism, wishful thinking, fantasy, suspension of disbelief, deletion of the boundary between dreams and reality, are not only not a handicap, but essential to the enterprise. ... We need our dreams and stories, our imaginaries. They are good for us. We need the cognitive rest from confronting reality all day, we need to be able to imagine alternatives, we need the pleasure of fantasy. But we also need to hang on to our awareness of the difference between dreams and reality. 
The more we realise both our fallibilities at knowing, and the more we realise that our only route to knowledge is through our fallible reason and senses, and the more we realise that the best we can do is repeat and repeat, thrash out what we think we know, hammer it into submission to our inquiry, the more religion, mysticism and other 'ways of knowing' has to retreat into the obscurity of mystical language.
Given religions penchant for morality, why isn't it the most rigorous of our philosophies? How wrong can we be in our search for alternative realities, alternative truths? It's not all religion's fault, though religion is often happy to jump on the bandwagon of unreason.
There is a profound irony in the situation - in postmodernist epistemic relativism. It is thought to be, and often touted as, emancipatory. It is supposed to set us all free: free from all those coercive repressive restrictive hegemonic totalizing old ideas. From white male western reason and science, from the requirement to heed the boundary between science and pseudo science, from the need to offer genuine evidence for our versions of history, from scholars who point out we have our facts wrong. ... Take away reasoned argument and the requirement for reference to evidence - by discrediting them via deconstruction and rhetoric, via scare quotes and mocking capital letters, and what can be left other than force of one kind or another? ... This is emancipatory? Not in our view. It is not emancipatory because it helps emotive rhetoric to prevail over reason and evidence, which means it helps falsehood prevail over truth. 
Even for benign religion? Well, precisely the same mechanisms, the same poor reasoning, the emotive language, the same style of faith, is used to justify a liberal believer's opinion as is used to justify a fundamentalist terrorist's opinion. The subsuming of reason and science to faith is the same in both cases. If you have faith in a benign God, from what stance to you argue against faith in a vengeful God? No matter how much you think you might reason it will do you no good, because you have already abandoned reason yourself - it's clear to all concerned that any reason you apply is only a token gesture, because to you your core is faith, not reason.
So, why does truth matter? It's hard figuring out what 'truth' is and how to get at it. We have only limited means at our disposal. I'd rather all our efforts go into finding the truth for what it is, not inventing 'truth' for which there's no evidence, no matter how cosy it makes us feel, no matter what the short term pragmatic value.
Why Truth Matters - Ophelia Benson, Jeremy Stangroom