Why do Deists believe in Heaven?

[ApeNotKillApe]

Funny how so many believe they're going to heaven even after that whole 'narrow road' nonsense in their own holy book.

My father died when I was twelve, I was taken along to visit his mother a fortnight or so after he died, and I remember being at my Irish Catholic grandmother's house, sitting on the sofa next to my little sister. My grandmother, still grief-stricken, and more Irish than one should be at midday, bent down in front of us and said, "You know he's in a better place now, don't you?" 

We both nodded plaintively, we might have each mumbled a 'yes', but the first thought that went through my mind was, "No, he's in Hell."
I didn't think that because I hated him, but because I understood Christianity and my father well enough to know that there was no way he was getting into Heaven, he was not a good Christian, he constantly swore and blasphemed, it was one of his defining qualities. My grandmother's statement struck me as very dishonest, I came to understand that she wasn't trying to console me and my sister, she was consoling herself and unknowingly acting with a complete ignorance of her religion.  That was probably the moment that I became an anti theist, though I didn't know it at the time.