Anyone could be a Christian, but a Christian could not believe simply anything. Here, twelve top theologians, all practising Christians, tackle ancient heresies and show why the contemporary Church needs to know about them. They argue that heresies are never finally defeated but always continue in some form or other as live options for belief.

Part 1 Heresies of the Person of Christ and How to Avoid Them

1. Arianism: Is Jesus Christ divine and eternal or was he created?
   Michael B Thompson

2. Docetism: Is Jesus Christ really human or did he just appear to be so?
   John Sweet

3. Nestorianism: Is Jesus Christ one person or does he have a split identity, with his divine nature separate and divided from his human nature?
   A N Williams

4. Eutychianism: Is Jesus Christ divine and human or a hybrid, a thing that is neither fully one nor the other?
   Marcu Plested

5. Adoptionism: Is Jesus Christ the Son of God by nature or by adoption?
   Rachel Muers

6. Theopaschitism: Is Jesus Christ able or unable to suffer in his divine nature?
   Michael Ward

   Part 2 Heresies of the Church and Christian Living and How to Avoid Them

7. Marcionism: Can Christians dispense with the God of the Old Testament?
   Angela Tilby

8. Donatism: Do Christian ministers need to be faultless for their ministrations to be effective?
   Ben Quash

9. Pelaginism: Can people be saved by their own efforts?
   Nicholas Adams

10. Gnosticism: Can people be saved by acquiring secret knowledge?
    Anders Berquist

11. The heresy of the Free Spirit: Are there two kinds of Christian, those with divine wills and those with human wills?
    Denys Turner

12. Biblical Trinitarianism: The purpose of being orthodox.
    Janet Martin Soskice