Everything has its time.
For example, before about the 1940s, black preachers in the South made a name for themselves by creating sermons that described a dark and hot Hell that awaited sinners. It was said that some were so gifted in this that congregations “could feel the flames licking the underside of the floor boards, and smell the brimstone through the cracks.” Heavenly descriptions, added almost after the fact, just served as a peaceful contrast of rest and happiness.
Importantly, this reached their congregations and gave them what they wanted, and caused many to mend their ways and resist temptation.
However, by the time of MLK, this way of thinking had pretty much collapsed. With the return of the soldiers from WWII, segregation in most of the US quickly and quietly collapsed.
At the time, many small towns across the Bible belt were ruled by cliques of various Protestant sects that pressured others to maintain the social order, which included segregation and social behavior. The veterans rejected this outright, as well, and refused to cooperate with a dictatorship of gossips.
A lot of social pressure suddenly got released in a hurry, and MLK was a the forefront of one part of it. He had evolved into a religious skeptic and rejected parts of the Bible in their entirety; but he saw within it the justification for social reform.
“King was originally skeptical of many of Christianity’s claims. At the age of thirteen, he denied the bodily resurrection of Jesus during Sunday school. From this point, he stated, “doubts began to spring forth unrelentingly”. However, he later concluded that the Bible has “many profound truths which one cannot escape” and decided to enter the seminary.”
The bottom line is that he could not have led a religious revival, because there was too much of his faith he did not believe. As soon as he got his PhD, with a plagiarized dissertation, he immediately started rabble rousing, something he was far better at.
Ahhh, that makes perfect sense.