Christ the firstfruits
The Lord commanded the ancient Israelites to present the first sheaf of the barley harvest to the priest. Then, the priest waved it before the Lord as a pledge of the full harvest that was to follow. This ceremony was to be performed on the 16th of Nisan (Abib; Leviticus 23:10). The Passover supper was eaten on Nisan 14 (Leviticus 23:5), and on the 16th came the offering of the firstfruits.
The wave sheaf of the firstfruits of the harvest was a type of Christ, the “firstfruits,” or pledge, of the great harvest that will follow when all the righteous dead will be raised at the second coming of Jesus. The apostle Paul wrote, “For if we believe that Jesus died and rose again, even so God will bring with Him those who sleep in Jesus. For this we say to you by the word of the Lord, that we who are alive and remain until the coming of the Lord will by no means precede those who are asleep. For the Lord Himself will descend from heaven with a shout, with the voice of an archangel, and with the trumpet of God. And the dead in Christ will rise first” (1 Thessalonians 4:14–16).
Christ rose from the dead on the very day that the wave sheaf was presented in the Temple. “Then they returned and prepared spices and fragrant oils. And they rested on the Sabbath according to the commandment. Now on the first day of the week, very early in the morning, they, and certain other women with them, came to the tomb bringing the spices which they had prepared” ( Luke 23:56; 24:1; Leviticus 23:14).
Thus, as the first sheaf was a pledge and an assurance of the ingathering of the entire harvest, so the resurrection of Christ is a pledge that all who put their trust in Him will be raised from the dead. “But each one in his own order: Christ the firstfruits, afterward those who are Christ’s at His coming” (1 Corinthians 15:23).
Would Lazarus’ resurrection invalidate Christ as the first fruits?
The scriptures give record to persons who were resurrected from the dead before Christ’s resurrection. These are: the widow of Zarephath’s son (1 Kings 17:17–24); the Shunammite woman’s son (2 Kings 4:18–37); the man raised out of Elisha’s grave (2 Kings 13:20–21); the widow of Nain’s son (Luke 7:11–17); Jairus’ daughter (Luke 8:52–56); and Lazarus of Bethany (John 11). There are also many saints in Jerusalem who rose at the resurrection of Christ (Matthew 27:50–53). https://bibleask.org/how-many-persons-were-resurrected-from-the-dead-in-the-scriptures/
These saints were resurrected only by virtue of, and in anticipation of, Christ’s own resurrection. As all the believers in the OT were saved by the atoning blood of animals that pointed to the future blood of Christ that was to be shed in the NT, likewise, all the dead saints before Christ got resurrected by hope and faith of Christ’s resurrection. In this real sense, Christ is the firstfruits of those who are made alive.
In His service,