In what ways did Christianity support the theory of Anglo-Saxonism?

Just to clarify, historians refer to Anglo-Saxonism as the set of cultural beliefs that influenced Anglo-American politics and intellectualism from the 17th to 20th century. Anglo-Saxonism describes a set of beliefs, rather than a theory. Early American Anglo-Saxonists supported ethical and legal principles that would later influence the establishment of democracy.
Early Anglo-Saxonism is associated with slavery and belief in racial superiority. Prior to Emancipation in the United States, the Bible was used to justify slavery. Non-Christian slaves taken from Africa were viewed as inherently sinful. There are numerous passages in the Christian Bible preaching servile obedience and slavery had been commonplace in the period during which the New and Old Testaments were written. Moreover, in the New Testament, Jesus never explicitly condemns slavery.
Anglo-Saxonism also contributed to the concept of Manifest Destiny in the mid-19th century. According to this belief, settlers of the United States were destined to expand throughout North America. This was justified as a divine right supported by God. Rationalization for Manifest Destiny also included the mission to spread Christianity to Native Americans.