I haven’t bought this book but it does have a good review by Justin Taylor.
Description according to monergism.com:
The Puritans have gotten bad press for their supposed lack of teaching on the doctrine of spiritual adoption. In Heirs with Christ, Joel R. Beeke dispels this caricature and shows that the Puritan era did more to advance the idea that every true Christian is God’s adopted child than any other age of church history. This little book lets the Puritans speak for themselves, showing how they recognized adoption’s far-reaching, transforming power and comfort for the children of God.
Here’s a trailer for the book:
Watch an interview with author here.