God turns around individual situations to change the world. He works in the lives of individuals, bringing them change and life and joy, as part of His master plan.
For an example, we can turn to Luke and see how God worked in one individual life as part of His great plan. He turned around Elizabeth’s life by removing her barrenness, bringing her joy. It was bigger that that, though: while He brought her joy, He brought the world the forerunner to Jesus.
It's amazing to see how God is in the details, and how He uses all the bits to make an amazing whole. It's equally amazing how His plan is not just to do great, overarching deeds that change the world, but to intervene in people's lives, bringing them good, and changing the whole world at the same time.
Elizabeth gets a baby, great joy, and the removal of the stigma of barrenness. At the same time, the world gets John the Baptist.