When you get right down to it, the OT is a pretty narcissistic story of ONE assemblage of people, telling the Jews that Jehovah created the entire World to place in dominion, and gave them the Promised Land for their exclusive use (of course, that served as pretty-good excuse to conduct a genocidal campaign against the 'Canaanites' who had inhabited their ancestral homeland as the indigenous people).
Of course, the point of Christianity was to internationalize a variation on the theme of Judaism, widening it from the ugly racially-motivated "insider (Jews as the 'Chosen People') vs outsider (all the rest of the World, AKA Gentiles)" thinking, where you HAD to be born-in Jew to have any input before Christianity.
Not that Christianity doesn't maintain the "us vs them" discriminatory thinking: it's only broadened it to 'believers who accept Jesus in their hearts as their personal Savior' vs 'heathens', where every member of the World population is potentially a convert. Jesus gave Christians the mandate to spread the World of their Lord, Jesus Christ to the far corners of the Earth, placing others under subjugation as they go.
In a nutshell, THAT'S the entire story of the past 1,000 yrs under "Christian" Nations (eg Spain, England, etc), with the conquest of N. & S. America, India, Asia, etc driven by conquest but operating under the sign of the cross while still following the examples found in the OT with a policy now labelled, "manifest destiny".
