"Truly, truly, 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 the Father.John 14:12(NASB)
The miracles of Christ were supernatural signs to authenticate His claims to be the Messiah of Israel as outlined in Scripture, but the WORK that Christ referred to was very different from walking on water, feeding 5000 men with bread and fish, raising people from the dead or casting out demons. Jesus did not say that Christians would do greater miracles but greater WORKS and He told us: this is the work of God is that you believe in Him Whom He has sent - and for all who have believed in Him God has prepared many works for us to carry out in His strength. All who believed would be empowered to do good works - but before this was to happen Christ would have to return to the Father so that the indwelling Holy Spirit could be sent to carry on Christ's work.. through each born-again believer.
The work to which Christ was referring was not walking on water or stilling the sea.. it was not feeding the masses with tasty food or raising dead people back to life but feeding the soul with every word that proceeds from the mouth of God and helping to raise spiritually dead souls into newness of life.. by grace through faith in the finished work of Christ at Calvary.
The work that was carried out by both the apostles then.. and the Church today, was to be founded on the spiritual work we are called to carry out - work that is to be accomplished in the lives of lost sinners who are dead in their trespasses and sins, estranged from God and facing eternal separation from Him - so that they might hear the good news of the gospel of grace, believe on the Lord Jesus Christ, become a new creation in Him - and receive forgiveness of sins and life everlasting.
The apostles of the early church and saints throughout the Church age were to continue the work that Christ began to do on earth. Indeed the first sermon that Peter preached after he had been baptized with the Holy Spirit on the Day of Pentecost, was a greater work than all the recorded work that was carried out by Christ in His earthly ministry. Physical food is not man's true need but spiritual food. Supplying man's basic necessities is not the Christian's priority but supplying their eternal needs.
The Lord Jesus raised a handful of people from physical death during His time on earth to authenticate His God-ordained, Messianic claims, but when Peter preached his first sermon.. 3000 souls were saved - 3000 spiritual resurrections were secured - 3000 people gained access to the Father's throne of grace, for mercy to find help in time of need. The work that Peter did on that first day of Pentecost was a greater work than had been secured during the entire recorded ministry of the Lord Jesus Christ. As Christ had said only a few weeks before: truly, truly, 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 the Father.
The apostles and certain others had been given the power to do miraculous signs during Christ's earthly life in order to authenticate His Messianic claims and those supernatural gifts continued to function during their lives, but the greater works that the apostles performed were connected with the salvation of the souls of lost men and women. God is still able to perform the same sort of supernatural miracles today, which continue to authenticate His deity - but the work that we have all been called on to carry out today is to proclaim the good news of the gospel of grace to a lost and dying world - for THIS is the work of God, that you believe in Him Whom He has sent.
Heavenly Father, thank You that Jesus Christ came into the world to save us from our sins, to die on the cross for the forgiveness of sins and that all Who believe on Him have life everlasting. Help me to carry out the work that You have prepared for me to do while there are still souls that need to know the truth of the glorious gospel of grace - that Christ died for our sins, that He was buried and rose again so that all who believe on Him will not perish but have everlasting life. This I ask in Jesus name, AMEN