Is the viewpoint that the biblical god is moral a valid perspective?

Christians believe there is one moral absolute, based from the nature of their god. I believe there are ideals which can be shown to be better than other viewpoints based on whether they benefit humanity or not. Now, their arguments rely on gods commandments from the bible. Mine are based on human nature, logic and rational discourse. Since their god allowed slavery, and commanded that people kill disobedient children and women who are not virgins when they got married, it becomes very obvious which mindset is actually benefiting mankind. Killing children who were disobedient does not help society. Killing women who are not virgins when they get married does not either. In fact, since a woman can break her hymen from other physical activities than sexual intercourse, you could be killing virgins by mistake. That viewpoint is not only harming people, it permits people to be killed for no mistake on their part. That is not only a proof that their belief system is flawed, it harms the very people they believe they are helping.