ectypal.net

...what God does in the world does not establish in any sure way what is true in eternity. God may appear in the world as three persons who do different things but this in itself does not tell us God is eternally triune and it could suggest the three divine persons are not in fact one God. We believe that God is one yet three persons not because of God's actions in the world but because Scripture says God is one and three persons. God's actions in the world are not self-explanatory. We need Scripture to tell us what they mean and imply.