Euodia and Syntyche were two Philippian believers who were in sharp disagreement with each other. Paul pleads with them to “be of the same mind in the Lord” (Philippians 4:2). That phrase, “in the Lord” or “in Christ,” is key to understanding how we can be united with each other and “rejoice” (Philippians 4:4). The phrase “in Christ” reminds believers that we are completely united with Christ.