any proof—while affirming that He is the Creator of all things—that would also establish that “nothing is comparable to Him.”
Rather, you have said: “We Christians, when we saw that things came into being, understood that something other than them must have produced them, for they are marked by opposition and constant change. Therefore we concluded: He is a thing unlike the created things, since He is the Creator of everything; and we did so in order to deny non-existence of Him.” Yet even if your argument did lead to knowledge of the Maker, it would tell us nothing beyond the bare fact that He is a creator—so what is left when it proves not even that?
There is no doubt that the Creator, exalted be He, must exist and cannot be nonexistent; this is self-evident and needs no demonstration for the vast majority of rational people and thinkers, though some have established His existence through theoretical proof. Still, nothing in your reasoning shows that He is unlike created things.
Your statement, “since He is the Creator of every thing,” only conveys that He created everything other than Himself; it gives no explanation that would rule out resemblance to Him. By such words you merely reveal your ignorance of rational proofs, just as you are ignorant of the revealed Scriptures. The Exalted likewise tells us of the inhabitants of the Fire, that they will say,
“Had we only listened or used our reason, we would not be among the companions of the Blaze.” (Surah al-Mulk 10)