By talking to them directly.
Which God did do with Adam and Eve. The rest of us are the children of the children of the children (etc) of Adam and Eve. (even if you think Adam and Eve only represented the first of us)
Wait...so now you believe the Adam & Eve story? I thought you agreed in the past that these were allegorical people. So if God 'speaks' to fake people who are supposed to relay the 'message' to their 'fake' children, where does that leave us real people? Because if you're going to go back all the way to the Genesis tale to back up the argument that God HAS spoken to us, then I really don't understand your line of reasoning...*said with love*