Having answered post #5 as per Admin request, I now want to make some general comments in case the problem is a misunderstanding between the relation between logic and knowledge about the real world.
First, the thread title is in error. Arguments, in the sense of logic, are not true nor false. True and false are values given to
statements; they can be assigned arbitrarily in the case of a theoretical exercise, but usually we consider a statement to be true if it corresponds to a fact about the real world and false otherwise.
Arguments are valid or invalid. An argument is valid if the conclusion is necessarily true whenever all the premises are true, otherwise it is invalid. An argument can also be sound or unsound; it is sound if it is valid
and if the premises are all true; in otherwords, the conclusion of a sound argument must be true.
The problem is that we can never be absolutely certain whether or not any argument is sound because we can never be absolutely certain whether or not the premises are true. So we can never be certain whether or not a logical argument is actually telling us something about the real world. In the end, we must always verify our assumptions, the premises, by empirical observation.
As a matter of fact, this is what science is all about. We test theories (the premises of a logical argument) by seeing whether we observe that the conclusion (the prediction) is true. If the conclusion is false (we see something different), then, assuming that the argument is valid (which is usually straightforward to check), we know that one or more of the premises are false -- that is, the theory as it stands is in error and must be fixed or thrown out.
So it is pretty easy to develop perfectly valid arguments for the existence and for the non-existence of God. This has been done since time immemorial. Where all these arguments fail is when people disagree that all the premises that go into these arguments are true; that is, these arguments are either not sound, or their soundness is in question.
There is a tragic flaw in our precious Constitution, and I don't know what can be done to fix it. This is it: Only nut cases want to be president. -- Kurt Vonnegut