Discipline. Endurance. Perseverance. The Christian life is like a racecourse, a marathon, set out before us. There is a reward in running well but particularly in finishing. Christians agree that this is a consistent pattern of New Testament teaching. But is the prize an extra bonus, a reward for having finished well? Or is the prize salvation itself? And if the prize is salvation, can it be lost? Or is everyone who has signed up and started the race...