Most contemporary accounts of the nature of faith explicitly defend what we call ‘the positivity theory of faith’ – the theory that faith must be accompanied by a favourable evaluative belief, or a desire towards the object of faith. This paper examines the different varieties of the positivity theory and the arguments used to support it. Whilst initially plausible, we find that the theory faces numerous problematic counterexamples, and show that weaker versions of the positivity theory are ultimately implausible. We discuss a distinct property of faith that we call ‘true grit’, such that faith requires one to be resilient toward the evidential, practical, and psychological challenges that it faces. We show how true grit is necessary for faith, and provides a simpler and less problematic explanation of the evidence used to support the positivity theory.