Atheism's answer isn't communism, for one thing.
Totalitarian communist regimes suppress religion because of one person: Karl Marx. You know the famous "opium of the masses" quote? Here's more of it:
"Religion is the sigh of the oppressed creature, the heart of a heartless world, and the soul of soulless conditions. It is the opium of the people. The abolition of religion as the illusory happiness of the people is the demand for their real happiness. To call on them to give up their illusions about their condition is to call on them to give up a condition that requires illusions. The criticism of religion is, therefore, in embryo, the criticism of that vale of tears of which religion is the halo."
In other words, according to Marx, oppressed people use religion to make their oppression bearable. If you remove their religion they will truly feel the suffering of their situation, and be spurred to rise up and revolt. Once socialism is in place and the people are no longer oppressed, they will no longer need religion.
Communist dictatorships have of course done little to alleviate the suffering of the people living in them. They see the persistence of religion as an outward sign of this, and thus pretending that the populace is happily irreligious by forcibly ousting religion becomes an ongoing requirement for international PR.
Marx may or may not be right about religion, but he could have told the Communists that forcing people to change, hide or cease their religious activities has little effect on their actual beliefs. (Incidentally, compare the terrible coercion by Communists to the peaceful activism which is now frivolously labeled "militant atheism". Compare that to "militant Islam" while you're at it.)
Communism's self-declared incompatibility with religion does not imply that atheism is responsible for the atrocities committed in the name of communism, even less than anti-Semitic atrocities can be laid at the feet of Christianity. This is because there are no atheistic commandments, no creed, no dogma, no central authority and certainly no "apostles". Nowhere does it say, "There are no gods, therefore do this and this." Communism declares that there are no gods while separately giving its followers commands, but does not link the two.
Atheism is a simple position on the existence of gods, a single conclusion and nothing more. It does not presume to contain answers to today's or any other era's problems. By precluding absolute trust in religious doctrine, however, it leaves one open to secular philosophies and moral systems, which provide earthly, tangible, verifiable rationales for their guidance. Those only interested in "power, wealth and materialistic pleasure" are not following these philosophies any more than they're following Christian morality.
On another topic, to Ruse's list of five "blots" on Christianity I would add three more:
- The continuing attacks on science and scientists in the interest of preserving the plausibility of Christian dogma, from Galileo to Darwin.
- The Thirty Years' War of the 17th century, fought between Christians with the singular goal of spreading people's own idea of God's Word.
- The continuing death of thousands in the Third and First Worlds as a result of intrinsically ineffective abstinence-only education and the defamation of condom use.