So long as we do not know ourselves, we remain co-makers of our travails. One can neither think oneself into a safe place, nor pray oneself into a protected place without first having done the necessary homework to sustain spiritual, mental and emotional composure in spite of what may appear to be unfamiliar, threatening or even impossible. The Spiritual Immune System needs strengthening not because the spirit has been compromised. Rather the beliefs, attitudes, assumptions and values which we have accepted and perpetuated without discrimination, have compromised the mind and predisposed it to unhealthy habits of thinking, speaking and behaving. Honest examination of one's beliefs will likely lead, directly or indirectly, to a hidden coffer of fears.
Fear is a universal condition, the great barrier to human spiritual growth.
Then our unknowns create more fears. In most cases this is but a temporary repression of what was never reconciled, only displayed. Thus does our buried fear putrefy and spread like an infection under the skin. But what's the use of pretending not to be afraid when one is already afraid. Like other instinctual impulses, fear can be useful.