(1) If there is a god, then there's something we should worship.
(2) There's nothing we should worship.
(C) There is no god.
(1), they say, is true by definition. God (on the sort of theism they're examining) is all-knowing, all-good, and all-powerful and something humans are obligated to worship.
(2) is a moral claim which they defend by making worship out to be something tremendously self-abnegating, and so inconsistent with human dignity.
Now, if worship requires unquestioning and unqualified obedience, it seems that the only theologically acceptable free act we can perform is the act of submitting our lives to God. And once we submit to God, we must abdicate our capacity for independent moral judgment. Once again, if God deserves all-in trust, praise, love, and so on, then to question--or even to wonder about--any of His demands is to sin. Actions done independently of God's commands, even if they accord with what God command, are nevertheless failures of obedience. (p. 151)I think Jews and Christians (I don't know about Muslims) will simply reject this account of what worship amounts to. Reread the last sentence. It makes it look as if God orders us about all day long. There's no reason why theists should understand God this way. In fact, the idea that God made humans "in his image" doesn't comport with the idea that we are robots under his constant command. No, we are like him--we are self-governing. If he does issue some commands--"thou shalt not kill"--how does it compromise human autonomy for us to "have to" obey them? On any objective morality, there are things we "have to" do. On the other hand, if we must define "worship" in this extreme way, I'd just reject (1), if I were a theist. No, it's not a part of the concept of God that we are his slaves. Note: it's "God the father" not "God the master." So: the argument seems easily dismissed by theists.
And yet, and yet. I think Aikin and Talisse do raise an interesting question. Namely: what is this thing called "worship" and how could it be good, not bad? Even if worshiping God is not a question of constant servility, how could it be self-respecting to prostrate yourself even just by bowing your head at a religious service? Isn't even that a bit servile--so a bit bad?
Then again, is "worship" even a necessary term? Perhaps the state of mind in a church or synagogue can be reverence--a much less submissive thing than worship. One could say congregants are experiencing a brief interlude of humility--and isn't it positive to periodically practice that virtue? Are they being slavish (bad) or are they briefly putting aside self, and focusing on the community? If you're entirely focused on the words of liturgy, you'll think worship is grovelling. But if you think about what people are actually experiencing, it may be something else.
Now I will "confess": I personally do not worship--I just can't do it, because I think there's nothing to worship. But I actually like being part of a worshiping group, at least from time to time. This is what always strikes me: the people in my particular reform Jewish congregation are movers and shakers. Every other day of the week, they have lots of individual power and wealth. Yet they come together and in some sense lower themselves, becoming just one member of a group. Standing to show respect, bowing, and various other acts, are ways of acting out this focus beyond the self. I find that just the opposite of repellent, and actually moving.
So--is worship incompatible with human dignity? It depends enormously on what worship is. I think a "reasonable atheist" will not jump to conclusions.