How can you have a personal relationship with God if he never responds?

I don't believe you can but that is my own personal belief. It all comes down to what you have faith in. A person who believes in God is going to have faith that God is watching out for them and trying to communicate with them in some way. Also, a person with faith in these things is not going to take a lack of noticeable communication to be a sign that there is no god, but will often believe that the absence of a message is THE message for them.