Through our earthly family, God gives us glimpses into the relationship that we have with Him because of the gospel. He is our Heavenly Father. As believers, we have been adopted into God's family & given a new name, a new family, & a new future (John 1:12). Over & over in Scripture, the Lord refers to us as His children & He as our Abba Father, our Daddy. As kids, our relationship with God the Father is first understood & shaped by our interactions with our own father.
It is also through the family that real discipleship takes place. God did not instruct youth pastors to bring up their youth group in the nature & admonition of the Lord; He gave that command to fathers (Ephesians 6:4). When it comes to the responsibility of disciplining & shaping the next generation, Scripture speaks directly to parents (Deuteronomy 6:5-9).
If parents are not there to love, instruct, & shape their children, who will be? We must be there for them. We must fight for them.