First none of the claims made are actually supported. Second none of the claims made are specific. Third none of the claims are even new. The fact that the claims are unsupported, unspecific, and old likely suggests an appeal to self as an authority combined with simple bias instead of an advancing concept.
In short, "this sucks, you're likely lying, and that's okay. Just try again."
Monotheism is the belief in one god. Followers of that god will generally make some kind of effort to do what he tells them to. If the god gives good commands, then they will do more good. If the god gives bad commands, then their behavior will in general be more evil.
Since the Christian god (and the Muslim god according to some) is inherently good and the Bible is full of commands to do good, turn the other cheek, love your neighbor, etc., monotheism is good.
1. Believers in a religion will tend to obey their god at least some of the time.
2. The main monotheistic religion's god commands good.
3. Therefore, believing in monotheism is likely to bring about good.
I don't want to argue about whether god exists here; but whether or not he does, we can surely measure the effect of belief that he does in this World.
There are a number of persistent myths that I would like to disabuse the World of, namely:
1. Myth: Religious people give more to charity. This is only true if you include donations to the churches to which they belong, for the purposes of building, preaching and proselytizing.
2. Myth: Religion comforts people. There is some evidence that those of a religious bent are happier than their atheist brothers and sisters... But evidence points to this being solely down to the infrastructure of a support network that meets up frequently and therefore cannot be counted as a benefit of belief.
3. Myth: Religion makes people behave more morally. There is no evidence to back up this claim. For instance, we can look at murder or rape rates in religious communities, states or countries and compare them to less religious couterparts... What we find is that religiosity is not correlated with more moral behaviour.
Sidetrack rant ("why it matters") I haven't yet seen any evidence that there's a God; I haven't yet seen any evidence that belief in God can do anybody any good. I have tons of evidence of monotheism causing harm such as intolerance, hindrance to science, disenfranchisement of women, prejudice against homosexuality, preaching against condoms and thus causing the spread of AIDS, etc.
To me, the debate about religion should be focused on the here and now. Arguing over the existence of a god for whom we have no evidence is a waste of time... I think that the focus should be on whether belief has any tangible benefits or harms associated with it. Unfortunately, like the death penalty's efficacy as a deterrent, most people's instinct here is wrong... Most people instinctively assume that having a death penalty would act as a deterrent but the fact is that it does not. Likewise, most people instinctively assume that religion is a comfort that makes people behave better but it is, when you look at it, just not the case.