Final answer:
Early Pentecostal preachers were strongly motivated by the belief that Jesus was coming again soon, a concept aligned with millennialism during the Second Great Awakening.
Step-by-step explanation:
Among the motivations for early Pentecostal preachers, d) The idea that Jesus was coming again soon is a statement that best describes one of the many strong motivations. This belief was shared by movements such as the Shakers and Millerites, who thought that the second coming of Jesus was approaching. Early Pentecostals, influenced by this millennialism, were motivated by the urgency to prepare individuals and communities for what they believed was the imminent return of Jesus Christ. This motivation aligned with the impulses of the Second Great Awakening, which centered around large gatherings at religious revivals, seeking to reawaken one's faith through intense, emotional experiences, and the belief that a better world could be established on earth, a characteristic also deeply connected to millennialist views.