Now, go ahead and specifically cite which persons (if any) you are referring to, here, by the phrase "the Greek philosophers", and then quote, from their own writings, or from whatever ancient writings give an account of their sayings, the exact things they wrote/said, upon which you imagine you are basing your claim. If there is one thing I know about the so-called "philosophers" of ancient Greece, it is that there was never, in a 1,000-year period, anything but a perfect unanimity between each and every one of them, on every single, solitary point they ever discussed. There was definitely NEVER any controversy between any of them, nor opposing schools. So, of course, if you could quote even one of those guys, showing that he held to "the idea of an unchangeable god", we MUST, then, come to the conclusion that every single other one of them, also, held to "the idea of an unchangeable god", and that not a one of them ever contradicted it! In other words, it MUST be entirely out of the question that any "Greek philosopher" ever held to "the idea of [a changeable] god" (what YOU champion). Also, of course, it simply MUST follow that, since at least one of them held to "the idea of an unchangeable god", then that idea must have, as you say, "come from the imagination of the Greek philosophers". Red is the colour of sarcasm.