Proving a Negative

Christians, as a whole, seem to believe that since scientists can not prove the nonexistence of God, then the only other option is that God must exist.  They try to shift the burden of proof from themselves to the rest of humanity.

There are two things going on here.

1. Nobody can prove that something does not exist.
2. The default conclusion is not that because something can not be proven that it must be true.  It is also not natural that just because someone believes in this mysterious, invisible, undetectable thing that their beliefs must therefore be respected.