Waiting on God is a big theme throughout scripture and it's a challenging undertaking at times but it's vitally important for God-fearing people to learn. Sarah and Abraham failed as they waited for the child of promise to be brought into their lives. They became impatient and decided to take matters into their own hands. The story that bring Hagar and, eventually, Ishmael, onto the scene is a sad one but one that holds many important lessons for us.