It was never God's intent for children to be without a family!
This is why scripture says He assumes the role of father to the fatherless and He sets the lonely in families. This is the heart of God - a good, loving and gracious Father. This is also the basis of His mandate towards us, the Church, to care for vulnerable children and families around us. Our call to care for the vulnerable and orphaned is rooted in God's care of us through Jesus.
That's what this book is about - the work of Christ on our behalf in the gospel.