Definitions of faith

https://plato.stanford.edu/entries/faith/#Aca

John Calvin defines faith as:
‘a firm and certain knowledge of God’s benevolence towards us, founded upon the truth of the freely given promise in Christ, both revealed to our minds and sealed upon our hearts through the Holy Spirit’ (John Calvin, Institutes III, ii, 7, 551)

On Plantinga’s version, theistic beliefs count as knowledge because they are produced by the operation of a special cognitive faculty whose functional design fits it for the purpose of generating true beliefs about God. Plantinga calls this the sensus divinitatis, using a term of Calvin’s. (For discussion of the extent to which Plantinga’s use of this term conforms to Calvin’s own usage see Jeffreys 1997 and Helm 1998.) 

Jeffreys, Derek S., 1997. “How Reformed is Reformed epistemology? Alvin Plantinga and Calvin’s ‘sensus divinitatis’,” Religious Studies, 33: 419–431.
Helm, Paul, 1998. “John Calvin, the sensus divinitatis, and the noetic effects of sin,” International Journal for Philosophy of Religion, 43: 87–107.