Mercy: What Every Catholic Should Know by Daniel Moloney ( published by Ignatius Press 2020:£13.99). The concept of mercy is an integral part of both the Old and New Testaments in which God is traditionally characterised as vindictive in the former and forgiving/loving in the latter. Is that an accurate position? Can God be vengeful if we believe that, ultimately, God is love? In this book, one of the What Every Catholic Should Know series, the author provides a clear and concise of this essential quality for living out the Christian calling.