Meeting God in Unanswered Prayer

Someone, apparently a young adult, wrote me recently and asked about prayer.  This person was having a hard time discerning the difference between worry and prayer.  He or she was wondering if prayer, although salutary to ourselves, really does have an effect on those we pray for.  Particularly, this person was worried about and/or praying for his or her parents who seemed to be getting further and further apart.  Did God hear his/her…