Dylan was deeply interested and involved in spiritual matters long before and after his three overtly Christian-themed albums. In the pics of his living room from the late 60’s, you can see a large Bible on one of those stands made for them. The 1968 John Wesley Harding album is full of Biblical references and themes, as had been previous albums dating back to the mid-60’s. His focus at the time may have been more on the Old Testament than the New, coming from a Jewish heritage and upbringing. The burning desire to share with others a spiritual awakening eventually subsides, and one returns to a "normal" spiritual life. Dylan was been to Jerusalem a few times, praying at the Wailing Wall.
Just because Dylan isn’t public with his current spiritual life doesn’t mean he doesn’t have one. He was also not public with his marriage to one of his background singers, and their child together. Does that mean his marriage and child are/were fads?! How many know Bob has a brother? To think we know all about his personal life is rather presumptuous.