Walls. Sometimes they are necessary, literally and figuratively. They shouldn't always be perceived in a negative light. In prayer, meditation, and art, they are stones of beauty, spirituality, and life.
Often times people don't build walls to close people out, but rather to protect whatever is left within.
Regardless, they are complicated and our lives are surrounded by them. Obstacles they may be, and hardships faced when knocking them down, Ralph Waldo Emerson believed that "Every Wall is a Door."