Find someone to talk with who won't be critical of whatever thoughts and feelings you need to explore. Don't believe it. Having your personal faith does not insulate you from needing to talk out and explore your thoughts and feelings. To deny your grief is to invite problems that build up inside you. Express your faith, but express your grief as well.
Some questions have answers.
Some do not. Actually, the healing occurs in the opportunity to pose the questions, not necessarily in answering them. Find a supportive friend who will listen responsively as you search for meaning. Memories are one of the best legacies that exist after someone loved dies. Share them with your family and friends.