I wonder what the early Christians knew about God when the scriptures were still being written. Now in saying that, I'm not trying, for instance, to make oral tradition equal to scripture like the Catholics do, but the Bible wasn't dropped down from heaven and intact.
And how do you interpret the Bible? Do you seek to understand the context in which each book was written -- geographical context, historical context, cultural, social, theological, philosophical, etc.? That can make a considerable difference in meaning. How do you determine if a passage is meant to be taken literally, or allegorically, etc.? That also makes a difference. Those are some reasons why there are so many denominations. And what about the canon? How do you know which canon is the correct one? Protestants, Catholics, and Orthodox have different canons. What about the church fathers? Do you give their writings any weight? The early church saw things differently than the later church.
I believe all these things factor into how I know God.