I believe that God prays in us and through us, whether we are praying or not (and whether we believe in God or not). So, any prayer on my part is a conscious response to what God is already doing in my life.
It is not outer reality that silence reveals, but our own innerness. Silence is essentially a surrender to the holiness of the divine mystery – whether we use these words or not. An atheist, calming his or her spirit in the peace of silence, is irradiated by the same mystery, anonymous but transforming. We are to listen. To what? To silence.