The inclusion of the much-beloved secular myth of the 'deist' George Washington, popular in atheist circles (except those that actually know some history), demolishes the article's credibility.
What evidence do you have to support Washington's belief in Christianity? Which specific claim about Washington are you refuting?
Washington's religious beliefs aren't quite clear. Everything I've read indicates that Washington at the very least was not a highly religious man, possibly being deist or at least keeping his religion very private. However, he was clearly not anti-religious either. I know he was baptized and raised Christian, and attended church with his wife(not always though). He claimed he'd hire any worker of any religion, atheists included, so long as they were good workers. He seems to have known the dangers religious tyranny and hatred could bring about, but not being anti-religious only discouraged that type of thing from occuring to prevent unnecessary strife rather than professing that religion was a bad thing.
Personally, I lean towards thinking he was a deist, at least later in life. In 1793 Washington thus summarized the religious philosophy he was evolving during his Mount Vernon years. How happenings would "terminate is known only to the great ruler of events; and confiding in his wisdom and goodness, we may safely trust the issue to him, without perplexing ourselves to seek for that which is beyond human ken, only taking care to perform the parts assigned to us in a way that reason and our own conscience approve of." George Washington