Many book reviews tend to rehash in compact form the contents of a book. I am not going to do that here. To attempt it would be an injustice to the book itself. But I highly recommend The Unseen Realm by Dr. Michael S. Heiser.
Dr. Heiser, a professor of Hebrew and Semitic Languages, takes us on a journey and exposes not only the supernatural world described in passages of the Old Testament, but shows how the New Testament references these passages, how it fills out our Christian worldview, and reclaims the purpose God has for man.
Many of us have read Genesis 6:1-4. And there have been questions about what it means (I'm sure you've asked them too). But, have you read Deuteronomy 32:8 ESV? Or how about Psalm 82? This is where the journey begins by looking at the original Hebrew texts as well as the worldview of an ancient Israelite. Questions about angels, demons, giants and even about God Himself are tackled point by point in scripture and in the ancient Semitic texts of the region. This book will help you fully understand God's plan for man's salvation and our place in his world -both earthly and heavenly.
For more information on Dr. Heiser, visit his website at https://drmsh.com