harm in liberal christianity?

Hi all,

What do you see and the harm in liberal types of christianity?  

I was raised in the Lutheran church.  As a teen-ager I realized that I just didn't believe in any religious nonsense.  However, much of my family are still deeply involved with their churches.  While I readily see significant problems or dangers associated with more conservative or fundamentalist types of christianity, I'm really struggling to define the harms of more liberal theologies- I'll talk mainly about Lutheranism, because it's what I know, but my understanding is that there are a number of denominations with similar philosophies:  They've had female clergy since the 1970's.  Despite some internal struggles, the majority of the organization is pretty much ok with gays.  Don't take a hard-line on abortion rights, and are fairly reasonable in their approact to sexuality.  They basically have a democratic organizational structure with a lot of power in the lay-people, instead of a centralized, top-down empire of the the Catholics.  No magical incantations to dead saints or to the BVM.  I don't recall ever getting hell and damnation shoved at me.  They mostly have seen a strong sense of racial and ethnic inclusiveness and social justice.  And I do see that they do a lot of charitable work within the surrounding community- my parents in involved with a church group that makes a lot of trips to disaster-stuck areas to help with rebuilding homes, for instance.  

For me the big, whopping harm is that the center of their belief system is just plain wrong- there is no god.  Working within the truth, whether pleasant or difficult, is always superior to falsehood in my mind.  My second problem is the slippery slope, that once you open the door to mild religious ideas, it can lead eventually to crazier and crazier ideas.  Do note that I've already called out the fallacy in my second argument by name.  I suppose that it's good that I can see some religious groups that can be allies in a lot of areas.  What's your take on this?