"The largest single group of Christians is the Roman Catholic Church. I think the Anglican community is next. Both believe in an ancient earth, not one 6000 years old."

As far as I know The Lutherans (except for a few esoteric spin offs who use the name 'Lutheran') also accept a 'scientific' age not a 'theologically derived' age.

But then, from Yahoo Answers Questions I have seen, many US 'Protestants'. do not accept their lineage of Christianity as being traced thru The RC Church, posing such revealing questions as "Are Catholics really Christians?"