The pattern of harvest, as established in the Old Testament, begins with “firstfruits,” then the main harvest, and finally the gleaning of the fields by the needy and destitute, assuring that not one kernel would be lost.
The very fact that we have borne the image of Adam guarantees that we will also bear the image of Christ. First the flesh, the earthy, then the spirit, the heavenly. First the man of earth, then the man of heaven. Thus Paul so confidently declared,
As we have borne the image of the earthy, we shall also bear the image of the heavenly (I Corinthians 15:49).
He could not more forcibly present God’s guarantee that the very fact you exist as a human being is proof and assurance that one day you will bear the image of God’s heavenly Adam, Jesus Christ. God always finishes the work He begins, including that of making man in His Own image which He began in the Garden of Eden.
The “Last Adam” is not an idle poetic expression that Paul used referring to Jesus. As the context of his words show, he intended to establish the fact that just as we all sprang from Adam the first man, and therefore bear his image, so in the very same way the “Last Adam” is the first spiritual man. The first Adam was the first of the old and earthy creation; the “Last Adam” is the first of the new and heavenly, or spiritual creation.
In Romans 5, the inevitability of bearing the image of the Man from Heaven is underscored. Jesus is the firstborn of the new creation just as Adam was the firstborn of the old creation. The work of Jesus far surpasses the work of Adam. What Adam did unto death, Jesus much more accomplished unto life. Jesus, the “Last Adam,” will make alive all who died in the first Adam.
For as in Adam all die, even so in Christ shall all be made alive (I Corinthians 15:22).
Bert Bauman The Gospel, page 16