The Apostle Paul wrote to the Corinthians telling them that he had been with them “in weakness, and fear, and much trembling.” I think Paul was referring to what clinicians would describe as “mood vacillation”. But, to put it in terms of plain English, Paul was saying that he had mood swings, that he battled anxiety and depression. And I suggest that this stemmed from genuine faith and genuine faith includes a lot of self doubt, awareness of personal demons, and personal insecurities.
A key element in the development of my faith has been giving up certainty and the compulsive need to be “right.” And when one does this, he/she often deals with “weakness, fear, and much trembling” in his/her day to day life. This is merely part of being alive and being open to the full gamut of human experience, the full gamut of spiritual experience. Toni Morrison described it as being “petal open.”
In closing, I would like to recommend reading Richard Rohr re the Apostle Paul. (You will have to google these terms. I’m’ still learning how to provide links!)