An innocent man, if accused, can be acquitted; a guilty man, unless accused, cannot be condemned. It is, however, more advantageous to absolve an innocent than not to prosecute a guilty man.
On the subject of the nature of the gods, the first question is Do the gods exist or do the not? It is difficult you may say to deny that they exist. I would agree if we were arguing the matter in a public assembly, but in a private discussion of this kind, it is perfectly easy to do so.