Religion and The God of the Bible are not necessarily tied together.
If I ask you what religion do believe in you can give me any number of answers in which none have anything to do with the God of the Holy Bible. In religion anything goes, it does not have to be based on culture, they way one is raised or where one lives a religion can be defined as anything you believe and give sacrifice to.
On the other hand if I ask you what is your theology you now have to give me a answer that defines who you are and what God you believe in. You have to define your God and what that God stands for. One might say I don’t believe in a God but in a idea; you still have to define it and what that idea stands for and how you stand for that idea. Theology wont allow you to get away with generic ideology or idolatry but it pins you to who you are and what you are.