Some religionists believe they have the infallible Truth. Evolutionary religion makes no provision for change or revision, does not provide for its own correction.  In the mortal state, nothing can be absolutely proved; both science and religion are predicated on assumptions. 
There is a reality in religious experience that is proportional to the spiritual content and transcends all human achievements. The convictions of this religious experience are unassailable; the certainty of such knowledge is superhuman.  True and genuine inward certainty does not in the least fear outward analysis, nor does truth resent honest criticism. 
Physical certainty consists in the logic of science; moral certainty, in the wisdom of philosophy; spiritual certainty, in the truth of genuine religious experience.  We let pressure develop stability and certainty; to accept challenges and face difficulties. 
The certainty of the God-knowing religionist should not be disturbed by the uncertainty of the doubting materialist; rather should the uncertainty of the unbeliever be mightily challenged by the profound faith and unshakable certainty of the experiential believer.  On the spiritual level, the need for finite proof gradually vanishes before the actual experience of reality.  Certainty extends only as far as one’s personal experience. 
In knowledge alone there can never be absolute certainty, only increasing probability of approximation; but the religious soul of spiritual illumination knows, and knows now.  Nothing which human nature touches is infallible. 
Of God, the most inescapable of all presences, the most real of all facts, the most living of all truths, the most loving of all friends, and the most divine of all values, we have the right to be the most certain of all universe experiences.  We can become more absolutely certain of the reality of the presence of God that lives within us than reality of a fellow being’s reality.