Bradley. answered...

The family is a key component to support us in God's plan for gaining immortality and eternal life. All of God's children (all the inhabitants that lived, are living, and will live on Earth) are inseperably connected to each other, both (physically) by our Earthly families and (spiritually) by our Heavenly Father.

Families help us to understand our divine heritage. In this, life takes on purpose and meaning. Our immortal spirits were created by our Heavenly Father before Earthly existance, and we are directly connected to Him in this way. As a spiritual family, our collective purpose on Earth is to follow the commandments of God that lead us to live in heaven with Him again.

Our spirits need to progress, learn, and grow. In order to achieve that, Earthly existance was created as our test. Our Heavenly Father knew that being exposed to opposing forces on Earth was the only way for us to gain knowledge and wisdom.

However, we will not always choose righteousness, and so our Savior, Jesus Christ, is that great mediator to pay the debt of our mistakes. He is the only way by which we can be saved from our sins and transgressions. He is the ultimate example by which direction we need to live our lives. With the support of our earthly kin, we can learn from each other, serve each other, and strengthen our mortal weaknesses by being disciples of Christ. Our families are a gift from God, and we can be together forever.