The original mandate given to man in Genesis 1v28 was to "subdue and have dominion". Unfortunately when Adam & Eve sinned against god, they lost their connection with God, and lost their spiritual authority.
Jesus came to give us back our relationship with God,and our assignment of dominion again. Jesus demonstrated the message, He lived out the message of bring heaven to earth where ever he was. He first called 12, then 70, and finally entrusted all believers with the assignment to go, as ambassadors of the Kingdom, to proclaim the gospel, to make disciples, to heal the sick, to cast out demons, raise the dead - to minister in power and signs and wonders.