[Religion] is predominantly evil and entirely deceitful, has only negative correlations statistically, and is frequently maliciously abusive physically mentally and emotionally. It has historically always obstructed education and retarded or impeded progress in whatever application it has ever touched. All the worst atrocities in history were done in the name of religion and our greatest advances were made in opposition to it. I’m an antitheist because religion is factually historically ethically and morally wrong.

One of the most pernicious effects of religion is that it tends to divorce morality from the reality of human and animal suffering. Religion allows people to imagine that their concerns are moral when they are not — that is, when they have nothing to do with suffering or its alleviation. Indeed, religion allows people to imagine that their concerns are moral when they are highly immoral — that is, when pressing these concerns inflicts unnecessary and appalling suffering on innocent human beings.

Religions have done far more damage over the centuries than good. Religion may help individuals to bear hard times and trouble and loss, but institutionalized religion of all stripes quickly becomes dangerous. Established religion always seems to breed a them vs us mentality that has lead to crusades, pogroms, ethnic cleansing, the Inquisition, genocide, civil war, and legal discrimination.

And yet people ask what's the harm of religion - and we cite all these different problems with religion: the global gag-rules and things like that , the oppression of different people - but there's a bigger harm with religion, and it's the reason why I'm outspoken about it, and that's because the average feel-good Johnny-in-the-pew person who is decent and kind and loving and good to their family and generally a good person to be around has polluted their mind to the point where they are unable to take credit for their accomplishments and responsibility for their actions. They are unable to interact on an interpersonal level with the people around them, to build a community in this cooperative society where that is absolutely essential. They have got this mentality that they are worthless without God.

Religion is an insult to human dignity. With or without it, you’d have good people doing good things and evil people doing evil things. But for good people to do evil things, it takes religion.

Religion is a by-product of fear. For much of human history it may have been a necessary evil, but why was it more evil than necessary? Isn’t killing people in the name of god a pretty good definition of insanity?

Religion has ever filled the mind of man with darkness, and kept him in ignorance of his real duties and true interests. It is only by dispelling the clouds and phantoms of Religion, that we shall discover Truth, Reason, and Morality. Religion diverts us from the causes of evils, and from the remedies which nature prescribes; far from curing, it only aggravates, multiplies, and perpetuates them.

Religion carries two sorts of people in two entirely opposite directions: the mild and gentle people it carries towards mercy and justice; the persecuting people it carries into fiendish sadistic cruelty. Mind you, though this may seem to justify the eighteenth-century Age of Reason in its contention that religion is nothing but an organized, gigantic fraud and a curse to the human race, nothing could be farther from the truth. It possesses these two aspects, the evil one of the two appealing to people capable of naïve hatred; but what is actually happening is that when you get natures stirred to their depths over questions which they feel to be overwhelmingly vital, you get the bad stirred up in them as well as the good; the mud as well as the water. It doesn't seem to matter much which sect you have, for both types occur in all sects....

In regard to the terrors as well as the superstitions and immoralities of religion, it will not do to urge that they are due only to the imperfections of the men who professed the various religions. If religion cannot restrain evil, it cannot claim effective power for good.

There are some forms of religion that must make God weep. There are some forms of religion that are bad, just as there's bad cooking or bad art or bad sex, you have bad religion too. Religion that has concentrated on egotism, that's concentrated on belligerence rather than compassion. … But then you have to remember that this is what human beings do. Secularism has shown that it can be just as murderous, just as lethal … as religion. Now I think one of the reasons why religion developed in the way that it did over the centuries was precisely to curb this murderous bent that we have as human beings.

Religion is an insult to human dignity. With or without it you would have good people doing good things and evil people doing evil things. But for good people to do evil things, that takes religion.

ONE OF THE most pernicious effects of religion is that it tends to divorce morality from the reality of human and animal suffering.

Religion is like drugs, it destroys the thinking mind.

Religion is a byproduct of fear. For much of human history, it may have been a necessary evil, but why was it more evil than necessary? Isn't killing people in the name of God a pretty good definition of insanity? Arthur C. Clarke, author