you can’t be serious…just saying “nobody knows if the universe began to exist” is not a legitimate counter to a bit of reasoning that claims to show that someone does know if the universe began to exist…
you say that you’re an (almost) lawyer: what you’re doing here is tantamount to this: you ask a witness, “did you see my client stab the victim?”, to which the witness replies, “yes”. then, you just stare the jury down and state, “well, nobody knows if my client stabbed the victim”.
nice try.
you need to to address the argument that has been presented to you, not simply state that no argument is possible. unless, of course, you want to argue that there can’t be any legitimate theistic proofs…
any way you slice it, you need to give me an argument, not just a statement.