The single blow from the Father was laying the sins of the world upon Jesus when the Father could not look upon Him because of that sin. Christ paid for that sin we have only to believe Him, repent confessing our own sinfulness trusting Him to change us.
This is not about physical healing, although God does do that, it is about our spirit being changed into a new creation by the Spirit of Christ coming to live in those who have repented and trusted in Him.
When God said "you will do greater works than I" He was not referring to the healings and other miracles. He was referring to the greater work of bringing the gospel to the world with the message of salvation for anyone who will repent and trust in Christ.
John 14:11-12 "…11 Believe Me that I am in the Father and the Father is in Me—or at least believe on account of the works themselves. 12 Truly, truly, I tell you, whoever believes in Me will also do the works that I am doing. He will do even greater things than these because I am going to the Father."
Those who wrongly interpret the "greater things" as miracles are missing the most important message of all, which is the gospel.
John 14:13–14
"13 Whatever you ask in my name, this I will do, that the Father may be glorified in the Son. 14 If you ask me anything in my name, I will do it."
All the work of evangelism must be done in the power of the Holy Spirit. The Holy Spirit knows the exact words every person needs and in what tone of delivery. No one can give a formula for this work.
God has given different gifts to each believer as well as different talents. We are to walk in our Holy Spirit gifts and talents and not in the flesh.
