Q. Re: John 14:12. I tell you the truth, anyone who has faith in me will do what I have been doing. He will do even greater things than these, because I am going to the Father. Where in history has any human being done anything greater than Jesus did?
A. In the sense of providing the means for our salvation no human ever has or ever could approximate the Lord’s work, because only He could save us.
But in terms of things ordinary humans can do, Jesus really had a very narrow exposure to the world. Take evangelism, for example. Paul spoke to and influenced many more people in his travels than the Lord did. And there have been many evangelists since Paul who have far exceeded his numbers. The same can be said for feeding the hungry, helping the poor, healing the sick, etc.