one can say that religion exists simply to facilitate us to become a good person.
Religion by nature has an orientation. "Okay, this is good and this is bad" despite the possibility of a grey area that is highly malleable by the general population's perception.
Other branches of knowledge on the other hand have no orientation. Some options may suppress the basic feeling of guilt and shame.
Take chemistry for example. One can be a great chemist who cures cancer or an evil chemist who helps to produce weapon of mass destruction. In both cases, the acquired knowledge of chemistry is utilized.
Acquiring only other branches of knowledge besides religion is not enough to become a good person.