We share a commonality with Lucifer/Satan (and all of the other angels) ... in that we are creations of God.Romans 8: 16 The Spirit itself beareth witness with our spirit, that we are the children of God:These verses speak of Christians (i.e. believers).
17 And if children, then heirs; heirs of God, and joint-heirs with Christ; if so be that we suffer with him, that we may be also glorified together.
Are you saying that Christians and Satan share a brotherhood ?
Yes, Jesus is the only begotton Son, in the flesh.
So ... is Satan ... of the flesh ?