It should be, “When my brother finally got back from serving overseas, my family was happy and proud.” When reading this out loud you would pause after overseas.
I assume you meant to ask, "What is a simile <em>in </em>"The Hands of an Angry God." So, one example is the simile in which the author compares God's wrath to a terrible flood (“The wrath of God is like great waters that are dammed for the present...”).