Are you saying OT believers did not have the Spirit of God in them?
If we believe the spirit of a man is in his soul of the man, then you could say the spirit was in the soul of the OT prophets. But the Holy Spirit was ‘upon’ the spirit not IN the spirit, not even with Moses. Until the Cross the Holy Spirit has not been in a man, except maybe Melchizadek because he had an eternal status as a priest forever.