The existance of a God isn't really the question.
Gods have always been created to answer other questions.
Why does it rain? Why is there suffering? Where does the Sun go?
As our understanding grows and we learn the answers to these questions, the God(s) that were created to answer them fade from importance.
In our current age, there is only one question left.
What happens after we die?
There is no way to answer that. It is the final question.
The only way science could ever answer it would be to prevent death. Without death, goes the last question and need for religion.