In the Western world, the idea that God could be angry with us is now implausible, and in this context assurance [faith] is little more than a sentimental belief in our own inherent goodness - exactly the kind of faith held by the reprobates. . . And the notion is now commonplace that because we can never have exhaustive knowledge, and all our knowledge takes place in a context, we can never have certain knowledge at all. Yet this simply fails to understand the nature of God's revelation of himself, and can ultimately not account for the certainty of faith that drips from every page of Paul's letters. . .
God has spoken to us in ways we can understand, given himself to us in the finite flesh of Christ and the finite words of human speech; while these revelations do not exhaust God in himself, they are yet true, reliable, and foundations for certainty.
-- Carl Trueman, Blogging the Institutes