"In the past decade some new and sophisticated arguments have been made for understanding religion as a natural phenomenon. Some of these arguments, moreover, have arisen as a result of new scientific findings that have changed the nature of the debate. What are we to make of this state of affairs, in which atheism has the better case, where its evidence involves new elements, which introduces new arguments, but where religion, so its adherents claim, has the numbers, despite its manifest horrors and absurdities?" (Watson, The Age of Atheists: How We Have Sought to Live Since the Death of God, Kindle Locations 302-305)
Watson has fallen under the non-evidential spell of uncritically believing that the genesis of history's manifest moral horrors is especially religious. Here Watson is preaching to a certain atheistic choir who will all nods their heads and say "amen." Perhaps Watson refuses to consider the manifest horrors of atheistic cultures? See, for example, here.
British historian Rupert Shortt has recently argued that the "religion is the cause of human evil" thesis is too simplistic. Shortt writes:
"It is above all unscientific to single out 'religion' (what religion? which manifestation of it?) for criticism, while ignoring both the colossal violence of twentieth-century anti-religious regimes, and the strife associated with other forms of social bonding, such as nation or ethnic group. In Northern Ireland, to cite an obvious example, religion is deeply interlaced with the legacies of British imperialism and Irish nationalism. In other parts of the world, religious affiliations often shade into ethnic differences, which in turn merge with claims to land, water, and oil. The tenth parallel is a case in point. Geography forms a major source of tension in several of the countries in this region, so faith differences can be exploited to intensify what are basically turf wars and other geopolitical conflicts. The subject also needs to be placed in the broader context of nineteenth-century and postcolonial nationalism." (Rupert Shortt, Christianophobia: A Faith Under Attack, xv)
The thesis "religion is the cause of evil" is simplistic and, therefore, false (sorry John Lennon et. al.)
One more point. I'll defend the ethics of Jesus over the worldview of atheism any time. Since on atheism there's no libertarian free will (and hence no moral responsibility) and no morality (viz., no justification for moral duties), then logically (following, e.g., Dostoevsky et. al.) "everything [moral or immoral] is possible." This may explain why Oklahoma City bomber Timothy McVeigh quoted as his final words the poem of atheist William Ernest Henley:
"I am the master of my fate,
I am the captain of my soul."
On atheism no moral justification is needed because none can be metaphysically given. We captain our own ship because there's no "Captain" who made and pilots the universe. Therefore there's no Kantian-type "duty" to do anything.