But irrefutability is overrated. Christian faith appeals to freedom and to love, both of which require the absence of irrefutability, what Hans Urs von Balthasar calls "the purely worldly power of persuasion." The truth of Christianity is simply Christ -- the Way, the Truth, and the Life -- the Truth that will set you free.
The kind of evidential power with which God manifests himself must be of the highest kind, precisely in virtue of the fact that it allows freedom because it makes men free. And it wants to overpower a lover that answers in freedom only in its own way -- by the evidential power of love ...Balthasar cites Blaise Pascal as the thinker who best understood this, quoting this from Pascal's Pensées: "Perfect clarity would please reason but harm the will. The proud man must be humbled."
Balthasar goes so far as to say the "only that person can truly recognize the Messiah who knows how to keep his secret."
This is not of course to ignore the command to preach the Gospel to the ends of the earth. Rather it is to realize that the value of that preaching will depend primarily on how faithfully the lives of those who preach it have been conformed to Christ and only secondarily on how objectively persuasive their argumentation might be.
The secret that must be kept is an open secret, but it will elude those who try to discover it solely on the basis of a "purely worldly power of persuasion."