There’s nothing wrong with someone believing that their deceased family member or friend is in heaven
Whether it’s true or not , literally doesn’t matter . It’s no harm no foul. The image of a guy literally believing that his grandmother Lucy is in perfect peace and bliss is a great thing to think of for those who wish to believe . And considering the fact that no one knows what happens after death then it truly is no issue with believing in that . And for those who are naturalist and believe that once we die we are unconscious forever there is nothing wrong with believing in that idea.
However, it’s important for people not to force their beliefs on anyone and allow everyone to believe in whatever they wish to believe .
So if you are grieving and your believing that your deceased family member or friend is right now in heaven then go ahead and believe . It’s positive anyway.