John 17
"Holy Father, keep them in Thy name ... that they may be one, even as We are" (v11). Jesus' prayer reveals the intimate relationship He has with the Father, and it also demonstrates His purpose in saving us: to bring us into that same relationship. "This is eternal life, that they may know Thee, the only true God, and Jesus Christ whom Thou hast sent" (v3). In some ways, eternal life begins the moment we know God through Jesus.
The outward sign of that new life is love (v22-26). As we love each other and love God, we become "one".