Carter's Definition of Christianity is Defensible:

Joe Carter is taking heat for a post [with a follow up here] that examines Barack Obama's theological views and determines they are not "Christian" (even though Obama calls them "Christian").

If you tell me that you’re a "Christian" I take that to mean that you subscribe to a common set of doctrines outlined in either the Apostle’s Creed or the Nicene Creed. Both of these creeds are ecumenical Christian statements of faith accepted by the Eastern Orthodox Church, the Roman Catholic Church, and almost all branches of Protestantism. They outline what it means to be a "mere" Christian.

Carter then examines why Obama's views flunk the test (see the rest of his original post).

Carter's definition of Christianity is rightly disputed but entirely defensible on historical grounds. It's the very same definition I use when I conclude the key Founding Fathers were not "Christian." And indeed Carter notes John Adams flunked the same standard that Obama flunked. He also notes that Obama's status as a true believer is ultimately irrelevant in terms of ability to be a good President:

But all of this misses the true underlying question: Does it really matter if Obama is an orthodox Christian? If we are talking about the state of his eternal soul, I would answer "yes." If we are talking about his effectiveness as a President, the answer is obviously "no." After all, John Adams was theologically unorthodox and yet a great President while Jimmy Carter was a horrible President while being a completely orthodox believer.

Lest we should be seen as giving Obama a special "in" with the theology of the Founding Fathers, I would note from what I observed, McCain to me didn't appear to be any more orthodox than Obama. Indeed, this nominal Christianity that believes in a Providential God but either rejects or downplays orthodox Trinitarian doctrine arguably fits better with the American Presidency than orthodox Trinitarian Christianity which is too exclusive for not just today's pluralistic society but the one America's Founders established. Indeed it's doubtful that we had an orthodox Trinitarian Christian President until Andrew Jackson.

Finally in this comment, Carter gives a list of historic Churches that define Christianity accordingly:

–The Roman Catholic Church
–The Eastern Orthodox Church
–The Assyrian Church of the East
–The Oriental Orthodox churches
–The Lutheran Church
–The Anglican Communion
–All Presbyterian Churches
–The Methodist Church
–Almost all Reformed churches

This is very similar to a chart that Dr. Gregg Frazer constructs on page 10 of his PhD thesis where he shows ALL of the established Founding Era churches defined Christianity the same way, except one...the Quakers. More on that later, but I would contend that the Founding Fathers' "theistic rationalism" was in a sense like Quakerism without the anti-war teachings.