Because He Came ...
I have an elder brother.
16 The Spirit Himself bears witness with our spirit that we are children of God, 17 and if children, then heirs—heirs of God and joint heirs with Christ, if indeed we suffer with Him, that we may also be glorified together.
Romans 8:16-18 (NKJV)
Once we become a child of God, our elder brother is His Son, Jesus. Think of it! Instead of making us slaves, or minions, as He was certainly entitled to do, He makes us joint-heirs with Christ. An adopted child has the same rights and privileges as a natural child. In the same vein, we have been "grafted" into the vine - adopted into the family.
What a privilege!