We use Esther as a biblical example of adoption. But Esther was raised by a family member, not strangers.
In all the laws laid out for the people of Israel, everything from instructions about textiles to medical concerns, not one word is written, not one law dictated, about adoption. People dealt with infertility either by resorting to polygamy (e.g., Hannah, 1 Samuel 1) or levirate marriage. People dealt with the death of parents through extended family. In either case the inheritance stayed within the family unit.
In the New Testament, Paul writes, “For you did not receive the spirit of slavery leading again to fear, but you received the Spirit of adoption, by whom we cry, ‘Abba, Father.’ The Spirit himself bears witness to our spirit that we are God’s children. And if children, then heirs (namely, heirs of God and also fellow heirs with Christ)… (Rom. 8:15–17). Note the contrast with slavery and the connection of adoption with inheritance.
In Galatians 4:4–5, Paul writes, “But when the appropriate time had come, God sent out his Son, born of a woman, born under the law, to redeem those who were under the law, so that we may be adopted as sons with full rights.” Notice the emphasis on rights. The contrast would be with slavery, in which a person had no rights, not even to his or her own body.
In Ephesians 1: 5–6 we read that God “did this [choosing us] by predestining us to adoption as his sons through Jesus Christ, according to the pleasure of his will— to the praise of the glory of his grace that he has freely bestowed on us in his dearly loved Son.” The emphasis here is on God’s choice, not ours. We did nothing.
In short, while biblical adoption is secondarily about love and affection, it is primarily a picture of choice and benefits, especially of inheritance.
Sometimes God chooses those who oppose us to help us see the truth. In the ironic story of Jonah, the lost sailors were more righteous than God’s prophet. In the story of Baalam, the donkey—not the person chosen as God’s mouthpiece—spoke the truth. In the case of The Childcatchers, an author who negatively interprets just about everything Christians do still gets some things right.