It comes down to what you were brought up believing. There are several religions that believe in reincarnation. There are over 2500 different gods and goddesses know to man.
If you believe in one of them and not the others you are an atheist to the other gods. Which god do you pray to for enlightenment?
Is it the Muslim god, the Jewish god, the Christian god, one of the Greek gods, one of the Hindu gods, one of the Celtic gods, one of the Egyptian gods?
There are so many, if your god is real and all the others are imaginary, how do you know? Did you do research on the others to make sure? Did you pray to the others to see if you could get an answer? Other religions that pray to their gods all affirm they have received answers to their prayers.
If there is only one true god then the prayers of the other religions would go unanswered. I want to believe there is a god out there, and sometimes I think there is because I grew up believing in it. If I had been born under different circumstances the god I grew up with would be someone else.