Secularism has never demanded an anti-religiosity but recognized the legitimacy of non-religiosities. Indeed, in diverse multicultures such as our own secularism becomes indispensable to the continuing life of religious minorities against majority or authoritarian formations of belief, and hence is not only not anti-religious but explicitly facilitative of variously religious lifeways as it is of variously non-religious lifeways.
I have been an atheist since 1983 -- over thirty years by now! after a Roman Catholic upbringing. I am quite happy to live a life a-thiest -- "without god(s)" -- myself, but the primary value of secularism to me has always been its entailment of and insistence on a pluralist practice of reason, in which we recognize that there are many domains of belief distinguished in their concerns, in their cares, and in the manner of their convictions. Our scientific, moral, aesthetic, ethical, professional, political beliefs, and so on, occupy different conceptual and practical domains, incarnate different registers of our lives, are warranted by different criteria. For the pluralist, reason is not properly construed as the monomaniacal reduction of all belief to a single mode, but a matter of recognizing what manner of concern, care, and conviction belief is rightly occasioned for and then applying the right criteria of warrant appropriate to that mode.
Pluralism is not a relativism or nihilism, as threatened bearings of fundamentalist belief would have it, but a rigorous reasonableness equal to the complexity, dynamism, and multifaceted character of existence and of the personalities beset by its demands and possibilities. For one thing, pluralism allows us to grasp and reconcile the aspirational force of the contingent universalism of ethics without which we could not conceive let alone work toward progress or the Beloved Community of the we in which all are reconciled, while at once doing justice to the fierce demands and rewards in dignity and belonging deriving from our (inevitably plural, usually partial) inhabitation of moral communities that build the "we" from exclusions of various construals of the "they." Pluralism allows us to reconcile as well our pursuit of the private perfections of morality and sublimity (my appreciation of the aesthetical forms of which requires my admission of the validity for others, whatever my atheism, of its faithly forms) with the public works of scientific, political, legal, professional progress.
It is crucial to grasp that the refusal of pluralism is reductionism, and that reductionism is an irrationalism. It is a form of insensitivity, a form of unintelligence -- and usually a testimony to and inept compensation for insecurity. In Nietzsche's critique of the fetish (Marx's commodity fetishism and Freud's sexual fetishes are surface scratches in comparison) this reductionism is the ressentimental attutude of the life of fear over the lives of love, the philosophical imposture of deception and self-deception peddled as truth-telling. To impose the criteria of warrant proper to scientific belief to moral belief, say, or to aesthetic judgement, or to legal adjudication is to be irrational not rational. Also, crucially, it is to violate and not celebrate science.
To call the celebrated (or at any rate noisy) militant atheistic boy warriors of today "secular thinkers" is a profound error. To misconstrue as the sins of religious faith as such the moralizing misapplication of faithly norms to political practices is to misunderstand the problem at hand -- and usually in a way that multiplies errors: Hence, our militant atheists become bigots tarring innocent majorities with the crimes of violent minorities, they lose the capacity to recognize differences that make a difference in cultures, societies, individuals all the while crowing about their superior discernment.
Those who commit crimes and administer tyrannies in the name of faith irrationally and catastrophically misapply the substantiation of aesthetic sublimities and parochial mores connected to some among indefinitely many forms of religiosity to domains of ethical aspiration and political progress to which they are utterly unsuited. Fascism and moralizing are already-available terms for these too familiar irrational misapplications. Meanwhile those who attribute these crimes and tyrannies to the aesthetic and the moral as such, as practiced in variously faithful forms, are inevitably indulging in reductionism. This reductionism in its everyday stupidity is usually a form of ethnocentric subcultural parochialism, but the militant atheists prefer their stupidity in the form of scientism, usually assuming the imaginary vantage of a superior scientificity the terms of which presumably adjudicate the unethical in moralizing and the tyrannical in progressivity because it subsumes ethical and political domains within its own scientific terms. In this, scientism first distorts science into a morality which it then, flabbergastingly, distorts into a moralism itself, thus mirroring the very fundamentalism it seeks to critique.
Secularism is a theoretical and practical responsiveness to the plurality of a world in which there is always more going on that matters in the present than any of us can know and in which the diversity of stakeholders to the shared present interminably reopens history to struggle. It is bad enough that today's militant atheists get so much of the substance and value of science, taste, and faith wrong in their disordering rage for order, but in calling their reductionist irrationality "secular thinking" we risk losing the sense and significance of the secular altogether, that accomplishment of reason without which we can never be equal to the demands and promises of reality and history in the plurality of their actual presence.