We Christians affirm “God is Personal” because God manifested and became incarnate in Jesus. So far so good.
However, God in Godness remains more mystery than knowable. We may “know” God in the sense that we know another person — partially, incompletely, tangentially. Most of us must admit that we don’t really know ourselves. Part of our not knowing comes from not remembering, part comes from the reality of “still becoming me” for each of us, part comes from living in denial (I could never be like that!) and so forth.
So, if you don’t really know yourself and I don’t really know myself, chances are good we don’t really KNOW another human being all that well. Even when we know that other person’s habitual responses, there is so much more to that person than predictable, habitual responses.
If we don't know ourselves very well, and we don't know another human person very well, we probably don't know God very well, either. Personal? Most of us haven't even gotten to kindergarten level with regard to "knowing personally".
God in God’s Godness — who can know God?