Final answer:
Early missionaries were driven by a blend of religious calling and the desire to spread the gospel and bring Christianity, education, and medicine to distant populations, seeing it as their duty to carry out God's work.
Step-by-step explanation:
The specific belief that motivated many early missionaries to endure the hardships of missionary work was a combination of wanting to spread the gospel and believing in their religious calling. These missionaries felt it was their divine duty to share Christianity, education, medicine, and so-called modernization to people in unchristianized parts of the world. They were driven by a sense of obligation to their faith and saw the missionary work as an extension of their spiritual commitment. Christian missionaries often saw their work as a fulfillment of a 'calling' by God. This could mean spreading religious teachings or bringing what they saw as aspects of civilized life to others. Whether it was about contributing to the society of Christian nations, providing education and medical help, or addressing perceived social issues, the motivation was deeply rooted in their faith and the belief that they were undertaking God's work on Earth.