While doesn’t change, our understanding of Him does via culture and religion. How the Jews understood Him before the exile is vastly different from how He was understood after the exile and even unto the days of Jesus and the early church and even now our view and understanding of Him is being renewed as we look deeply as the life and ministry of Jesus Christ and see the Love of the Father as it is.
While true the Bible and nature does reveal who God is, I also feel there are reflections of God in other religions as they have made contact with God or at least come to knowledge of Him and try to understand Him. What makes the Bible unique is that it revels the love of God through the person and ministry of Jesus Christ.