The counter-cultural message of the Christian faith is that a critical part of salvation is in discovering our true self through our relationships. The incarnation reveals that our faithfulness to God is expressed in the context of the finite time and physical reality of our world. If, as Genesis suggests, we were created in the image of God, then as God found expression through the relationships made possible through creation, do we reflect that image of the Divine through relationships as well.
The challenge of narcissism is the discovery that we are not the center of the universe. I am part of a matrix of relationships and life does not center on me. That does not mean that I should be a doormat and allow myself to be walked on. Jesus is never depicted as a doormat. Jesus knew who he was and remained true to the image of God within himself but he also came not to be served but to serve others. As was true of Jesus, so you are an important part of something larger than yourself. Within the confines of our finite reality, that truth is reflected in how we relate to family, neighbor, church, denomination, and world. We are connected.
To belong to the Body of Christ is to recognize that connectionalism in the context of our loyalty to, or worship of, God. “For as in one body we have many members, and not all the members have the same function, so we, who are many, are one body in Christ, and individually we are members one of another.” Romans 12:4-5. The Body of Christ, much larger than any one congregation, is the laboratory in which we experiment with how to live out those relationships that finally are to be lived out in the world that God loves. To abandon the laboratory is to cut ourselves off from the sustaining relationships that teach us how to live reflecting the image of God in the world.