It is based on the story of Hosea from the Bible. It doesn't take place during Bible times but during the 1800s during the gold rush period. A great story for anyone to read.
Francine Rivers' book "Redeeming Love" is a Christian novel. It has many parallels to the book of Hosea in the Bible. It tells a story of God's unconditional love and redemption.
The story is set in the Gold Rush of the 1850s, but Rivers book is actually a retelling of the book of Hosea. The book has a PG rating, but the crux of the author's point is that God loves His people unconditionally.
Yes, Redeeming Love is based on the Bible -- specifically, the story of Hosea. Hosea was commanded to marry a prostitute, who later committed infidelity by returning to prostitution.