Before you incarnate as a soul, you assemble the group of souls you need to teach you and who fit the life lessons you need, particularly in earlier life. In this way, using your vision as a soul, you choose your family, many of whom you will have had a relationship with in prior lifetimes. You see, soul dynamics replay and shift throughout the lives of a human.
It is often vital to experience friendship with a past life enemy just as it can be as important to quarrel with one who you were greatly aligned with in a previous life. It helps you to explore the energy within yourself and, in essence, that is all that your family does. Your family group allows you to explore the energy within yourself.
– From Family Peace