What was the main difference in doctrinal beliefs between Martin Luther and John
Calvin?

Calvin had the idea that there was two group of people; the Elect and the non-Elect, which were chosen by God to be saved or not. Predestination was a key idea in Calvin's theology. He believed everything was already planned before even you were born. Luther believed that the state and the church should be separated.

Explanation:

Luther believed that the state and the church should be separated. The state should have all the power. While on the other hand Calvin believed that the state and the church should not be subject to one another and vice versa.

Explanation:

when world war i broke out across europe in 1914, president woodrow wilson proclaimed the united states would remain neutral, and many americans supported this policy of nonintervention. however, public opinion about neutrality started to change after the sinking of the british ocean liner lusitania by a german u-boat in 1915; almost 2,000 people perished, including 128 americans. along with news of the zimmerman telegram threatening an alliance between germany and mexico, wilson asked congress for a declaration of war against germany. the u.s. officially entered the conflict on april 6, 1917.