The secular objection referred to here is this:
So one reason for "atheism" (on the face of it a metaphysical position) is this political issue, which plays out in the United States in different ways than in Britain. Here there are no bishops in the House of Lords (if only because there is no House of Lords), but very few openly atheist politicians get elected, and there is a religious presence at many public events.
But Grayling's main concern is ethical. Nietzsche's main complaint about Christianity in The Antichrist, as I remember it, is with Christian ethics, or what so-called Christians have promoted as ethics. For instance, in section 38 he writes:
What has become of the last trace of decent feeling, of self-respect, when our statesmen, otherwise an unconventional class of men and thoroughly anti-Christian in their acts, now call themselves Christians and go to the communion table? . . . A prince at the head of his armies, magnificent as the expression of the egoism and arrogance of his people--and yet acknowledging, without any shame, that he is a Christian! . . . Whom, then, does Christianity deny? what does it call "the world"? To be a soldier, to be a judge, to be a patriot; to defend one`s self; to be careful of one`s honour; to desire one`s own advantage; to be proud . . . every act of everyday, every instinct, every valuation that shows itself in a deed, is now anti-Christian: what a monster of falsehood the modern man must be to call himself nevertheless, and without shame, a Christian!-Jesus opposes pride, greed, aggression, and so on, and yet there is little sign of his having had any influence at all on the most visible "Christians" around (i.e., basically, conservative politicians, whether openly political or presenting themselves primarily as religious leaders). So again we have atheism as opposition to a political phenomenon. And there are certainly ethical issues related to this. The Bible says little about abortion, for instance, but for some Christians issues like this and gay marriage are the most important issues of all. (I don't mean that it is crazy for Christians to think that their religion should make them oppose abortion. Only that such opposition: a) is not explicitly a big part of what the Bible says, and b) feeds the idea that others have that Christianity is a cultural or political movement rather than something more spiritual.) Or, at least, so it seems. People with more liberal views might be inclined to identify religion, and hence theism, with conservative moral beliefs.
But this leaves what Nietzsche thought of as true Christianity untouched (not that he was a huge fan of that either, but he saw it as being a very different animal). And his thoughts on the nature of Christianity are not a million miles away from Dostoevsky's (see The Idiot especially, which I believe Nietzsche read), whose thoughts on the subject, in turn, are not far from those of many of Christianity's admirers. So the angry opposition seems to be more to what might be thought of as sham Christianity, not the real thing. God has little to do with it, except perhaps as a kind of symbol associated with the moral and political right-wing.
Part of what the angry atheists do not (appear to) object to, and what they therefore often seem to miss in their attacks on "religion," is explained in this passage from Charles Guignon's introduction to The Grand Inquisitor (pp. xxxvii-xxxviii):
What is the cure for pride and egoism? We can understand Dostoevsky's answer only if we try to understand one of the deepest strands of Russian spirituality--the immense importance accorded to "kenoticism" as a way of life. Kenosis refers to Christ's act of self-emptying--his submission to the most extreme humiliation and suffering in order to do the will of the Father. In Russian belief, this self-abasement and self-abnegation has set a model for all humanity. To live the kenotic way of life is to follow the example of Christ, accepting suffering in meekness and humility.Like Nirvana, kenosis has a rather negative sound to it. But this could partly be the fact that we hear it from a misguided position. Compare Schopenhauer (the last words of Book Four of Volume I of The World as Will and Representation):
by contemplation of the life and conduct of saints, whom it is certainly rarely granted us to meet with in our own experience, but who are brought before our eyes by their written history, and with the stamp of inner truth, by art, we must banish the dark impression of that nothingness which we discern behind all virtue and holiness as their final goal, and which we fear as children fear the dark; we must not even evade it like the Indians, through myths and meaningless words, such as re-absorption in Brahma or the Nirvana of the Buddhists. Rather do we freely acknowledge that what remains after the entire abolition of will is, for all those who are still full of will, certainly nothing; but conversely, to those in whom the will has turned and has denied itself, this our world which is so real, with all its suns and Milky Ways, is nothing.And we should also remember the more obviously positive aspect of Russian Christianity, such as this teaching of Farther Zosima:
Love all of God’s creation, both the whole of it and every grain of sand. Love every leaf, every ray of God’s light. Love animals, love plants, love each thing. If you love each thing, you will perceive the mystery of God in things. Once you have perceived it, you will begin tirelessly to perceive more and more of it every day. And you will come at last to love the whole world with an entire, universal love.According to Guignon (p. xli) "there is no personal salvation in the Eastern faith, but only salvation for creation as a whole," which is not exactly what Schopenhauer believes but which fits his anti-egoism nicely.
In short, there seems to be a kind of religion (or just philosophy or ethics, if we think of Schopenhauer and, perhaps, Wittgenstein) that is not what atheists oppose. What they do oppose, judging by Grayling, is mostly a set of political and moral issues, combined (in Dawkins' case at least) with the fundamentalist version of theism. Many believers also reject this kind of theism as a form of idolatry. It's tempting to say that what they really oppose is idolatry. And that what they offer instead is idolatrous worship of the absence of idols (as Wittgenstein almost said in The Big Typescript). And that what the rest of us want (it could be just me, but I don't think so) is no idolatry at all.
UPDATE: Leiter on Grayling (with added Nietzsche) here.