In pointing us to the example of Jesus Christ, Philippians 2 is very direct in commanding us to "do nothing from selfishness, but in humility regard one another as more important than yourselves". This calls us to confront the seemingly logical justifications we have for being selfish, and to understand that being like Christ and showing love requires joyful sacrifice.  Video of this service is also available:  https://www.youtube.com/watch?v=P6-aUcQGiyQ&t=5528s