In order to communicate things of importance between different groups of people with different traditions of reasoning, you must find some means of building a common discourse.
My own proposal for this is to identify the background conceptual models and lineage of each tradition to see how each is rational and then find ways to compare them in different contexts with mutually agreed objective standards. That's based pretty much on the principles of integrative negotiation plus the principle of tradition-bound reasoning.
For example, God is "ultimately implausible" mostly in the tradition that began with the 18th c French philosophers, peaked with Voltaire, and represents largely their reaction to the religious wars and consequently blaming "organized religion." But we are also a product of Hume and the Scottish Enlightenment, Aristotelian and Aquinan reasoning and so on, and several other traditions that are less dogmatic in their atheism and in their certainty that God, social order, and morality are completely dissociable. By not respecting the fact that God is perfectly rational within some traditions of reasoning, we miss the point and refuse to engage the argument fairly.
Also, by not recognizing that a number of different traditions of reasoning are alive and well in jurisprudence, politics, religion, and even within science, we miss the chance to figure out what they are really arguing about.
I think the valuable thing about *secularism* as manifested most dramatically in the Deists of Locke's tradition was not the implausibility it rendered to the supernatural, but the fact that it promoted a form of increasingly universal discourse by focusing on things that were least specific to particular other traditions. The liberal university tradition of modern times is a deliberately self-reflective discourse where we make every effort to make it as universal as possible. However, we have also found that it can only be taken so far. The extremes of poststructuralist gibberish are a logical result of trying to take rationalist discourse so far skeptically that we discount every possible totalizing system or grand narrative, and we end up with implicit stories ones that are worse than the ones being deconstructed. Atheism is one of the artifacts of the Enlightenment tradition off slightly to the side of scientific traditions.
With increasingly universal discourse comes the possibility of the rule of law, and so on. But only when there is an underlying social order supporting it. That was Burke's insight, and also Toqueville's, I think.
American conservatives often take Burke and Toqueville to the point where they see secularism as a kind of totalizing system equivalent with militant atheism. That's an error. There are many more religious secularists than atheist secularists. Religious secularists are people who implicitly recognize the tendency of competing totalizing systems to dominate discourse and so want to "keep religion out of the public square." They are largely motivated by the recognition that big religions tend to suppress little ones, which is why the most active secularists historically have been small active Protestant churches and Jews. They have the most to lose by having a state religion, as much as the atheists do.
Religious conservatives see secularism itself as a form of competing religion to theirs, partly because they miss the point that it is a more universal discourse, but also because they correctly observe that discourse that becomes too universallized also loses much of its social function and its overall coherence, unless it also becomes a totalizing system like that of religions. Thus Atheism becomes a quasi-religion because it cannot be coherent and serve the solidarity of a group of intellectuals without a narrative akin to that of religion.