The plan of Salvation: We are here to prove our worthiness to go back to heaven and live with our Heavenly Father. And Jesus Christ made it possible to return to Heavenly Father, if we obey His commandments and live righteously with love for each other, while here on earth.
Families are important to God the Father. The purpose of parents & marriage is to provide opportunities for others to come to earth to fulfill our salvation missions here on earth.
The devil is cross because he can't obtain a body, so it's his mission to prevent us from returning to our Heavenly Father.