There is no reason to argue about the validity of religions. There is no completely solid evidence pointing towards the existence or nonexistence of deities; thus, no truly logical argument can be formed and the argument cannot be ended in any way beyond someone rage quitting.
It's like arguing about whether Superman would beat Goku in a fight. It's inherently illogical to argue about it no matter who you think would win, since the two have never even encountered one another. There is no solid logical foundation that any argument can be made on, and all that will result from any argument about the battle is an assload of salt.
Also, on a similar note, "burden of proof" is just bullshit used to pass the responsibility of proving a point onto someone else. It's ultimately just a smugger way of forfeiting an argument. The burden of proof falls on anyone who is making any argument. Take, for example, a court case. Both the defense and the prosecution are assigned to prove the defendant's innocence or guilt. If burden of proof fell fully on one side or the other, then there would only be a prosecution or a defense, not both.