The third Aliyah in Mispatim talks about care for the convert. We must take special care of the convert, widow, and orphan because Hashem will be their protector. The entire basis of the slavery of Mitzrayim was to show the Jewish people exactly how Hashem works. He will hear the cries of the oppressed, and always save the underdog. It is our job to ensure that there are no underdogs, and that we are all caring for each other.