The connection between the growth of the Spanish Empire and the spread of Catholicism can be best summarized by the following response:
After Spain merged the kingdoms of Aragon and Castile, it acquired Granada and was able to use it as a launching point to spread Christianity to the Americas.
This response reflects the historical context where the unification of Spanish kingdoms, particularly Castile and Aragon, and the completion of the Reconquista with the capture of Granada in 1492, laid the foundation for Spain's expansion into the Americas. Spain saw the spread of Christianity, particularly Catholicism, as a critical component of its imperial mission, led by figures such as Christopher Columbus, who sought to convert indigenous populations as they established colonies.