John 14:12

"He that believes on me, the works that I do shall he do also; and greater works than these shall he do; because I go unto my Father."

Because He goes to the Father, the Holy Spirit will come and do the greater work through the believer. Just as Jesus marveled at the centurion, this work will take great faith as Jesus mentioned in Matt 8:8. I consider my job is not to figure out if or how it the world it will be done, but to believe it. And in believing it will require great faith so long as it is not manifested, since after it is manifested it is known and evident. It will be in that day no longer the evidence of things not seen.