Not this again....
It is not up to atheists to define a god then disbelieve in it.
It is up to theists to define their god. If they can't provide demonstrable evidence and/or reasoned argument to support THEIR claim that a god by THEIR definition exists, the disbelief in that god is completely rational.
So far, none of the gods that have ever been defined to me by theists have ever met their burden of proof.
It is not up to atheists to define a god then disbelieve in it.
It is up to theists to define their god. If they can't provide demonstrable evidence and/or reasoned argument to support THEIR claim that a god by THEIR definition exists, the disbelief in that god is completely rational.
So far, none of the gods that have ever been defined to me by theists have ever met their burden of proof.
You'd believe if you just opened your heart" is a terrible argument for religion. It's basically saying, "If you bias yourself enough, you can convince yourself that this is true." If religion were true, people wouldn't need faith to believe it -- it would be supported by good evidence.