Check out this thread where I am debating atheists on whether moral rules, moral choices, moral accountability, human dignity, human rights, and ultimate significance of moral actions are rationally grounded on the atheist worldview.Warning, the thread contains swearing!

Here is the original starting post for the thread:

I noticed that a tension between two positions taken by certain atheists. First, they say that morality is an illusion fobbed on us by our genes. Second, they say that the God of the Bible is immoral, or that the Christian church is immoral.

I have a question about this, and maybe you can help me to understand the apparent contradiction. If moral behavior evolved over time, then it seems to me that it varies by time and place. This means that the standards we have today in the place where we live now are not really better or worse than at any other time and any other place. The evolved moral standards are just arbitrary conventions.

If this is true, then in what sense can atheists consistently press the problem of evil, the immoral behavior of God, and the immorality of Christian church in history?

Here is what I have come up with so far:
1. The atheist is expressing his personal preferences (I wouldn’t do it that way)
2. The atheist is using the arbitrary standard of his time and place to judge God and the church (we in this time and place wouldn’t do it that way)

Here is one of their comments, which I thought was about as good as an atheist can do on atheism:

The morality we all appeal to when we make moral judgments is at least 90% the result of the social conditioning we have all received. Where that conditioning contains a strong religious component (most places throughout history), religious values will have a high place. In the modern West, the religious component is weaker, and we now condemn slavery, crusades, inquisitions, and wars between Catholics and Protestants, all of which were once firmly believed to be sanctified by God. (There is a whole thread on this subject just now under “Faith and Religion” above. So far only the person who started the thread and I have posted on it.)

The other 10% consists of personal views arrived at by reflective people on the kind of world they’d like to live in. That portion of it is personal preference. It differs from a personal preference for chocolate over broccoli in only two ways: (1) Its object involves the behavior of other people and their interactions rather than that of the individual alone; (2) when two people have different preferences, they cannot both have their way, and so they are in conflict.

If you want to learn about these issues at a deeper level, there is also a good paper by Bill Craig on the problem of rationally-grounding prescriptive morality here. My previous posts on this blog on this topic are here and here. The first post is about whether atheists can use a made-up standard to judge God for his perceived moral failures, the second one is on whether meaningful morality is rational on atheism.