The key here is “one body in Christ”. Jesus is the head, we are the body. Whatever is true of the head is true of the body. When you look at a person you don’t look at their head and body as separate, and so it is with us for we are one with Christ. We are in Him and therefore we have become one spirit with the Lord. As He is so are we in this present world. See yourself as one with Christ. As 1 Corinthians 11 tells us if we will rightly discern the body of Christ, we will live healthy lives and we will not die early. To rightly discern His body we acknowledge that we ourselves are one with Him and therefore we do not speak evil of ourselves. We also do don’t speak evil of other believers for they too are one with Him. We also recognize that His body was broken so that our bodies could be made whole. We are the body of Christ.