My view is that faith in a proposition requires stopping one's search for evidence and making a commitment to take a risk on that proposition--and maintaining one's commitment in the face of counterevidence. This applies to both religious faith and more mundane cases of faith, such as faith in a friend. This view is spelled out in 'Can it be rational to have faith?' (reprinted here, in a version that might be easier to understand), where I also explain when and why it is rational to stop one's search for evidence and make a commitment. These conditions are further spelled out and defended in 'Instrumental Rationality, Epistemic Rationality, and Evidence-Gathering'.
'Faith and Steadfastness in the Face of Counter-evidence' explains when and why it is rational to maintain a faith-commitment in the face of counterevidence: why it is rational to continue to act on faith, and why it is rational to continue to maintain a belief based on faith. This work is informed by 'Rational Faith and Justified Belief', which explores the relationship between faith (on my view) and belief (on a number of views).
An undergraduate-accessible version of my work is here: 'When is Faith Rational?'.
'Reason and Faith' is an encyclopedia article that explains the various accounts of faith in the literature and how they relate to rational belief.
Other work in progress explains why faith in the sense of deference to authority is a special case of faith in the sense I defend, and how rational faith can shed light on the problem of disagreement (contact me for these papers).