The short answer is that ideas have consequences. It makes a life-and death difference as to which religion, which philosophy, which worldview, is the truth of the matter. Either we find out or continue in our self-destructive confusion. And, no, reasoning does not need to lead to hostile confrontation.
The hostility does not come from reasoning, it comes from resistance to reasoning, resistance to being open to correction by truths. Truth (reality) does not get out of the road for anybody, truth is the road. So we had better learn how reasonably to navigate it.
The attack on reason is no longer so much from a rigidly fundamentalist Christian point of view as from post-modernism having wafted into the life of Western Civilization. If secular science has failed us, then it must be because reason itself is not a valid tool for resolving vital issues — or so we have concluded. But science is different from secularized science.
Some post-modernists are sincere, reacting to the obvious and massive failure of secularized science and reason over the 20th century. But science and secularized science/reasoning are two quite different things. Secularization is a metaphysical decision, though seldom recognized as such. And the option least imaginable by almost anyone is that reason is God’s way, and that it ought to be the Judeo-Christian way. Almost no one thinks of God as being reasonable, let alone holding the intellectual high ground.
The fate of those who believe truth to be relative, however, is to become the victims of every charlatan and manipulator coming down the road.
Advertisers, media people, lawyers, politicians, and spiritual leaders are taught how to influence persons through fundamentally dishonest means, through emotional appeal, shame, guilt by association, etc.Fact and logic are intentionally and selectively factored out of the discussion. Students in captive audience classes (mandatory and coercively enforced school attendance) are taught that truth and morality are relative — and are behaving with appropriately disastrous consequences.
We must cut to the chase, and force the issue before especially the young: For what are you willing to die? For what are you willing to dedicate and sacrifice your life, your fortune, and your sacred honor…, if not for the truth? Are you willing to stand, come what may, to defend the open arena of honest public discussion and truth-testing? What do you want to pass on to your children and grandchildren…., if not a respect for truth, righteousness, and love?
Loss of truth has led directly to the lethal malaise in dying Europe. With no truth, there is nothing much left to live for, except “feeling good”, and that, after a while, gets boring. Europe is dying of boredom. The trashing of truth comes from two sources: (1) deep despair about life, and (2) willful intent to manipulate the public. In the end, it comes from the father of lies. Only dishonest persons can benefit from the trashing of truth.
And furthermore, manipulators do not really believe truth to be relative even though naive and gullible folks can be suckered in for a while. No one can live by relative truth in actual practice. Promoters of it want the rest of us to believe truth to be relative, and hence not defend our truth, only so that they can insert their version of objective truth unopposed.
That is betrayal of the most profound sort, and should be firmly treated as such. But there is a relatively easy way to find out who is and is not sincere: Ask (yourself first, then the other): If you were wrong, would you want to know? And are you willing to work together to find ways to test between our opposing views to see which is right?
If there is no reasonable and honest response, you know that you are not in an honest conversation. You are in spiritual warfare. As John Macmurray told us, all thought is for the sake of action, and all action is for the sake of relationship. There is no escaping the intimate connection between what we think and how we relate. Ideas have relationship consequences. If you want your relationships to go well, as many po-mo’s do, you must clarify your ideas and commitments.
 Read, for example, After the Ball, by Marshall Kirk and Hunter Madsen, one an expert in intelligence testing, the other an expert in advertising, both well equipped to mount their self-styled “propaganda” program to convert America to acceptance of homosexuality. The Episcopal “liberal” program of the 1990’s to do the same thing in the Episcopal Church was (for anyone who had eyes to see) a blatant mind-control program. But Episcopal conservative leadership was either too ignorant, prudish, or cowardly to stand up to the nonsense. And worse, they did not want to be told how they might win the struggle for sexual sanity. They had no concept of marshalling evidence and presenting a compelling case. They had been “post-modern-ized”, and so were out-debated, out-flanked, and out-maneuvered by persons who had no intention of allowing any thing so dangerous to their program as honesty.  See his two books, Persons in Relation and The Self as Agent.