I would self define as agnostic. I don't think whether god exists is an important or answerable question.
I do think religious studies is an important subject though as you can't understand huge swathes of history and indeed current affairs without understanding the roots and differences not only between religions but also denominations within each religion.
Religion explains why the puritans colonised the US, why the middle east has the issues it has, why so much of Africa has conflict and even why Ireland has some of the domestic laws it has - i.e. abortion.
To be ignorant of so much of why the world is as it is currently is hugely damaging to someone. These things influence our lives today just as much as anything else and is important context to making personal moral and ethical decisions.
Whilst I don't subscribe to any religions, I am interested in understanding other's perspectives and points of view. Being well educated on a variety of subjects such as this is important to being an engaged citizen as much as anything else.