The following arguments against the existence of God are valid.

My opponent is using terms incorrectly. Validity, for the purposes of formal logic, actually has nothing to do with truth. To say that no one can create a "logically valid argument" disproving God is completely incorrect. Again, the definition of valid from several sources: Wikipedia: The term validity in logic applies to arguments or statements. A logically valid argument is one where the conclusion follows from the premises. An invalid argument is where the conclusion does not follow from the premises. A deductive argument may be valid but not true. In other words, validity is a necessary condition for truth of a deductive syllogism but is not a sufficient condition http://en.wikipedia.org... Cambridge dictionary of philosophy: An argument is valid if it is impossible for the premises to be true and, at the same time, the conclusion false. Critical Thinking by William Hughes and Jonathan Lavery (My logic class textbook): (pg 186) The term formally valid argument is defined as an argument such that, if it's premises are true, then its conclusion must also be true. I would challenge my opponent to find a reputable source that agrees with their definition of validity when used for the purposes of formal arguments. By definition, the following is a valid argument: Unicorns do not exist God is a unicorn Therefore, God does not exist. or, to be less tongue-in-cheek: Omnipotent beings can't exist. God is an omnipotent being Therefore God cannot exit. Both of these arguments are equally valid according to the rules of formal logic. Truth does not enter into validity at all. If my opponent is asking for empirical evidence that disproves the existence of God, then that is another matter entirely. The whole point of faith is belief without undeniable evidence. If we had hard and fast evidence that God did or did not exist, there would be no need to debate the matter. My opponent has chosen to hide the true question behind an skewed definition of a commonly used logical term. What they truly want to know is: "can anyone disprove the existence of the Christian God empirically?" The answer is: not yet, or else there would be a lot fewer Christians on the planet. But neither has the existence of the Christian God been proven empirically. The question posed by my opponent is nonsensical. They chose to begin a debate using their own, made-up definition of the word "valid," setting their opponent up to answer a question that is, as of yet, unanswerable by people on either side of the issue. No one would accept this debate if it were properly named: "Disprove the existence of God empirically, or I win." My opponent is correct- by their definition of valid, no one will be able to formulate a valid argument disproving the existence of the Christian God. As I have illustrated, using the correct rules of formal logic, doing so is quite simple. This is an empty debate, which was what I hoped to illustrate at the very beginning. I think that if my opponent wins, since we are really debating nothing at all, it will be a very empty victory. Should they like to re-word the debate question to open the topic up to actual discussion regarding the premises of an argument against the existence of God, I would happily accept.