On the other hand, the idea of taking up the sword on behalf of a "creed" is not something Washington or the authors of the Declaration ever advocated; and the description of a "mission," in Mr. Bush's remarks, made people wonder if he was not becoming delusional. There is nothing to suggest anything of the sort in the Founding documents of America.
William Flax
That is what a creed is. Somehow you are confusing religious creeds with creeds in general.
However, aside from nitpicking over one word, the substance of the assertion still stands.
Washington fought for the principles included in the Preamble, so I assume he agreed with them. Since he agreed with them, it is reasonable and logical to assume he would apply those same principles across the board, as extended to all men.