The perfect drug?

Is religion the perfect drug? I'm sure most people are aware of or have opinions on or have at least heard that famous Marx quote of religion being an opiate of the people. I'm wondering though that if you could make a purely intellectual argument on the issue of religion and what it does to or for human beings as a drug? How has religion been used as a tool to manipulate the consciousness of masses of people? How has it been used by people to manipulate each other?
How has it been used in struggles of liberation? Does religion have a sort of stimulant or calming power over the mind? How has religion been used to both create and build community and also isolate groups of people and even kill?

Perhaps we'd need to expand the word religion into not only the theological/moral/spirituality realms of which people generally associate with the word and look at various "cults" such as the cult of advertising, the cult of beauty, the cult of propaganda, the cult of capitalism and various political-ideological cults (evidenced by nationalism and State worship) that serve as a sort of religiousity for people in ways that perhaps specific theologies don't. I said cult of capitalism didn't I? Well is there such a thing? Do people really worship money? Or perhaps is it by the very function of living in a capitalist system, one of the sole means by which a person can "transcend" the reality of their lives? I think the key is examining how religion (again, beyond the scope of particular theologies) becomes a sort of opiate, a sort of perfect drug that keeps people either docile and content in the illusions of freedoms and opportunities or angry and on edge. What IS IT that dulls our capacity for critical thought? What nurtures it? There are certainly benefits from belonging that religion offers but is it something that we inheirently want or is it something truly socially constructed and designed to serve varying purposes in a given society? Can you have community without an imposed religiousity of some sort? I'm not trying to say that religion is a drug only to raise the question of the function it serves in both the individual sense but also (and most importantly to my mind) in the larger structures of power.
I'd like to really engage this issue in a non-threatening manner so if you do respond, please don't do so out of the desire to simply attack me. Thanks.