You, however, are not in the flesh but in the Spirit, if in fact the Spirit of God dwells in you. Anyone who does not have the Spirit of Christ does not belong to him.
Romans 8:9 ESV

This probably refers to the Holy Spirit dwelling within us, but it could also be our own spirit in alignment with his, subjected to the law of the spirit of life. A Godly inclination as opposed to a sinful inclination.

“Does not belong to him” doesn’t mean that God (or Yeshua) is no longer sovereign over this person, but that the person is not a member of Yeshua’s chosen people. He maintains a foreign allegiance and is under eternal condemnation from God.