Question

Why did it take 38 years from the time Luther wrote his ninety-five theses until Lutheranism was accepted at the peace of Augsburg

Answer 1

The Catholic Church and its major secular ally,the Holy Roman Emperor,were not about to give up their monopoly on power through Catholic Christianity without a fight.

This led to prolonged religious wars;by 1555 both sides were exhausted,and agreed the somewhat fudged Peace of Augsburg to paper over the cracks.