Moral relativism and Christianity

It is astounding to see the efforts of those who preach extremism and moral absolutism inspired by the Christian Bible. The current Pope, former Cardinal Joseph Ratzinger, denounces moral relativism and continues to build outrageous arguments against birth control, including the use of condoms.
One wonders, though - has Ratzinger even read his own holy book, the Bible?
What does he have to say about the plethora of moral relativism or contradictions that exist in this so-called inspired word of God?
For instance, God, in his wisdom, orders us in commandment number 6 - thou shalt not kill. Yet, in the course of stories recounted in the Bible, God has no problem killing people - even innocent children! What about his prophet, Moses - who kills an Egyptian while no one else is watching, just for kicks!
If the Christian God, as recounted in the Bible, cannot keep any degree of moral absolutism or adherence to his 10 commandments, what right does Ratzinger or anyone else have to preach against moral relativism?
Meanwhile, people like Ratzinger who preach absolute doctrine, such as standing against the use of condoms, have blood on their hands - the blood of millions of people becoming infected and dying with HIV. Where is the concern when misguided dogma contributes to human deaths?
I would urge anyone who really wants to see the injustice, contradictions, and frank absurdities present in the Bible to peruse the Skeptic's Annotated Bible online.