Does Jesus promise in John 14:12 that miracles would continue?
"Most assuredly, I say to you, he who believes in Me, the works that I do he will do also; and greater works than these he will do, because I go to My Father" (John 14:12).
In the context, Jesus is giving his apostles instructions about the future after his death.
First, we need to ask what kind of works is Jesus referring to. It is true that Jesus did refer to the miracles that he preformed as works, but it wasn't limited to just miracles. Jesus saw that his efforts to teach the Gospel and bring the lost to God was his work as well. "The blind see and the lame walk; the lepers are cleansed and the deaf hear; the dead are raised up and the poor have the gospel preached to them" (Matthew 11:5). "The things concerning Jesus of Nazareth, who was a prophet mighty in deed and word before God and all the people" (Luke 24:19).
If Jesus was referring to his miraculous works, we run into a problem. He said that those who came after would do greater works than he did. How can that be? One of the evidences that Jesus is God is the fact that no man could do the signs that he did. "Men of Israel, hear these words: Jesus of Nazareth, a Man attested by God to you by miracles, wonders, and signs which God did through Him in your midst, as you yourselves also know" (Acts 2:22). As the crowds noted, "And many of the people believed in Him, and said, "When the Christ comes, will He do more signs than these which this Man has done?"" (John 7:31). Jesus also said "If I had not done among them the works which no one else did, they would have no sin; but now they have seen and also hated both Me and My Father" (John 15:24). Jesus was unique in the number of miracles he did, the variety of them, and the strength shown in doing things never seen before, or after. How could those who believe after him do greater works than Jesus?
"Pentecostal people cite Jesus' words in John 14:12, "He that believeth on me, the works that I do shall he do also; and greater works than these shall he do." Then they say that we must not be believers because we do not do the works or miracles of Jesus. If we were truly believers, we would do the works (miracles) of Jesus and even "greater works than" Jesus did. What shall we say to this?
"First, Pentecostal preachers cannot do the works of Jesus. They cannot walk on water. I have tried to get them to take just one step across a baptistry (length-wise) by walking on the water, but they have never done so. They cannot feed 5,000 people with 5 loaves and 2 fish and take up 12 garbage bags of fragments. They cannot raise the dead. No, they cannot do the works of Jesus. Neither can they do "greater works than these." Are they really believers?"
[Larry Ray Hafley, "Some Short Shorts," Guardian of Truth XXXVI:15, pp. 456-457]
If we realize that Jesus is talking about the work of teaching the world and converting the lost, then the statement in John 14:12 makes sense. "For in this the saying is true: 'One sows and another reaps.' I sent you to reap that for which you have not labored; others have labored, and you have entered into their labors" (John 4:37-38). Jesus laid the groundwork for turning the world upside down. Though some were baptized by his disciples while Jesus was on the earth (John 4:1-2), it wasn't like the response that came after his resurrection when 3,000 responded to the message on one day (Acts 2:40-41). "Then the word of God spread, and the number of the disciples multiplied greatly in Jerusalem, and a great many of the priests were obedient to the faith" (Acts 6:7).
Notice that Jesus said that those who believe would do greater works "because I go to the Father." The reason greater works could be done is because Jesus arose and ascended into heaven. If Jesus was talking about miraculous works, this does not make sense. Why would it take Jesus leaving to have greater miracles on earth? However, if we realize that Jesus is referring to the work of converting the world out of sin, the meaning is clear. "Now if Christ is preached that He has been raised from the dead, how do some among you say that there is no resurrection of the dead? But if there is no resurrection of the dead, then Christ is not risen. And if Christ is not risen, then our preaching is empty and your faith is also empty" (I Corinthians 15:12-14). The power of the Gospel lies in the truth that Jesus arose from the dead. Until that happened, the greater works could not be accomplished.
For the apostles, there was another advantage to Jesus' leaving.
"Nevertheless I tell you the truth. It is to your advantage that I go away; for if I do not go away, the Helper will not come to you; but if I depart, I will send Him to you. And when He has come, He will convict the world of sin, and of righteousness, and of judgment: of sin, because they do not believe in Me; of righteousness, because I go to My Father and you see Me no more; of judgment, because the ruler of this world is judged. I still have many things to say to you, but you cannot bear them now. However, when He, the Spirit of truth, has come, He will guide you into all truth; for He will not speak on His own authority, but whatever He hears He will speak; and He will tell you things to come. He will glorify Me, for He will take of what is Mine and declare it to you." (John 16:7-14).
The Spirit came to given the apostles remembrance of the things they saw and to teach them the things they had not been ready to learn while Jesus was with them. It was through their teachings that the Spirit convicted the world of sin, righteousness, and judgment.
"For I am not ashamed of the gospel of Christ, for it is the power of God to salvation for everyone who believes, for the Jew first and also for the Greek" (Romans 1:16).
"For the message of the cross is foolishness to those who are perishing, but to us who are being saved it is the power of God" (I Corinthians 1:18).