I care about truth, so I would like others to believe only that which is true. Since I believe religion to be false, it follows that I think an ideal world would contain no religion. One of the many ways a utopia would differ from the current world is that in a utopia, all will have decided, of their own accord, to convert their places of worship into places of learning: on every corner of every city, libraries rather than churches. To the extent that I believe this to be a positive vision, and to that extent alone, I may rightly be counted an adversary of all religion.
However, there are worse things than false beliefs—suffering and injustice, for instance. Many atheists are quick to point out that religion often is a cause of both; thus do we have a thread of eloquent moral critique all the way from the Baron d’Holbach to Christopher Hitchens. These atheists are right: eliminate religion, and you often eliminate the sole rationale for a familiar manifestation of injustice or oppression.
But there is a line to be drawn. Religion sometimes is a force for good, its vacuous foundations notwithstanding. Likewise, and more importantly, religion is not by any means the only source of problems in the world. Human corruption runs far deeper than that. There are, of course, particular problems in the here and now that would vanish into smoke were religion to cease to exist, but what other problems would then appear to the fill the void? People need few excuses to hate one another, and religion is only one excuse—take it away, and you may be assured that people will find others.
This is why I do not think religion is the enemy. The best possible world might not contain religion, but the next best one easily might. I believe the true battle lines are drawn not between the religious and the nonreligious, but between the humanistic and the anti-humanistic, the noble and the corrupt. These qualities cut across the full religious spectrum: good people come equally from both ends, though they are always rare.
When you are trying to gauge whether others are your enemies, do not ask them what they believe about gods and spirits. Ask them, rather, which is more important: that everyone believe as they do, or that everyone live in happiness, with justice? If they say that their doctrine is important, but far more important is whether one is good to others, then, whatever else they believe, these are your friends. But, if they say that being good to others is secondary; or, if they say that life is not meant for happiness; or, if they say that we will have peace and justice only once all have been made to kneel to right doctrine—if they say these things, then, whatever else they believe, these are your enemies.