Some early Christian teachers, such as Justin Martyr, Clement of Alexandria, and Origen, believed that God could been known through a consideration of philosophical arguments.  Tertullian, on the other hand, maintained an extreme fideism, believing that Christian faith is actually contradicted by human philosophy.

Luther emphasised the fallenness of human reason, and the necessity of faith in overcoming reason’s impotence.

Calvin followed closely the Pauline outline sketched above.  He held that a seed of knowledge of the divine has been planted in each human heart.  This knowledge has been suppressed and perverted, such that it leads inevitably to idolatry, rather than to a true knowledge of God.  For Calvin, the Bible is the self-authenticating word of God, not requiring the exercise of fallen reason to demonstrate its truth.

Pascal had a powerful experience of God at the age of 21.  God is so great, he maintained thereafter, that unaided human reason cannot possibly comprehend him.  ‘The heart has its reasons of which reason knows nothing.’

Kierkegaard also held that faith must transcend reason, given that God is infinite and reason can only apprehend the finite.  ‘The real task is not to understand Christianity but to understand that one cannot understand it.’  To philosophise about God is to avoid our duty of commitment to him as a transcendent Person.  Faith is irrational surrender, a leap into the dark unknown.

Barth followed Calvin in insisting that God may be known only by the self-authenticating word of God.  Natural theology is repudiated.  Although nature does indeed reveal God, in our blinded state we end up worshiping gods of our own making.

Cornelius Van Til also stressed the utter sinfulness of the human mind.  Rational appeal is futile.  The task of the Christian apologist is to lay bare the contrasting presuppositions of believer and non-believer, to show that the Christian world-view is the only truly rational one, and to call human beings to obey God’s command to believe.

For Alvin Plantinga and others, belief in God is not derivable from other beliefs, but is itself a ‘basic belief’, requiring no rational support.  Such basic beliefs, which also include knowledge gain through sense-perception and self-evident truths, form a framework for understanding reality, and a basis for developing and assessing acquired beliefs.

In summary, then, fideism in its various forms and strengths mounts a challenge to evidentialism, which maintains that faith is only warranted when reason is satisfied by the available evidence and supporting arguments.  Extreme or simplistic forms of fideism, which in effect ask thoughtful to commit intellectual suicide, do not commend themselves.  Moderate fideism, which allows evidences to supplement and support belief, while emphasises human depravity, the authority of the word of God, and the necessity of the enlightening and enabling work of the Holy Spirit, would appear to be the best approach.

Based on J.W. Ward, art ‘Fideism’ in New Dictionary of Christian Apologetics.