Martin Luther effected a seismic changed in western history when he successfully broke Western Christendom into two parts: Roman Catholic and Protestant.
One effect of this was to put more power in the hands of monarchs, who no longer needed papal approval to legitimize their reigns. This led sometimes to the abuse of power, as, for instance, when the Stuart kings in Great Britain interpreted their "divine rights" very aggressively to make power grabs that led to the English Civil War. This effects us today because as a result of the political crisis in Britain, philosophers such as John Locke developed theories of Natural Law that asserted that monarchs ruled by the consent of the governed, who had a right to rise up against tyranny. This gave the American colonists grounds to stand on when, in 1776, they rebelled against British rule. We can say that because of Martin Luther's revolutionary theology, the west eventually developed a theory of human rights that facilitated a rise in democracies such as the United States.
Second, Luther's intense emphasis on "sola scripture," or the Bible as sole authority in theological debate, led to a need to translate the Bible from Latin into vernaculars and a consequent emphasis on literacy so that people could read the Bible and interpret it for themselves. Literacy gains in the west, which continue to benefit us to this day, can arguably be traced back to Luther's reformation.