The knowledge of faith is a practical knowledge, a knowledge of the heart rather than of the head, a knowledge with a personal, profound, soul-absorbing concern, for it pertains to something in which the self in its inmost essence is concerned, something in which my existence, my life, my soul, my salvation is involved. Faith is an approbation and an acceptance, therefore, and a knowledge of a testimony coming to a person; but it is an acceptance of that testimony in its application to oneself, a receiving of the word of the preaching of God, not as a human word, but as the word of God (1 Thess. 2:13). It is an approbation by the self of the gospel as a message which God sends to me personally.
— Herman Bavinck