The first: The first Adam departed from God, went his own way to lead us into sin and broken relationship with God and no hope. We are totally fallen yet still image bearers.
The second: The second Adam, a.k.a. Jesus Christ the Son of living God, lived a perfect life and gave himself a ransom for many. As in the single act sin came into the world a solution for sin came in one act on the cross in the form of a perfect sacrifice creating a finished work the Gospel. Perfect because he did everything his father asked him to do. The perfect work is also called the Gospel. Did I say Gospel? ; )
First: The cloven tongue of the Old Testament was the serpent in the garden enticing God’s creation into sin.
Second: The cloven tongue of the New Testament is the Spirit descending on the disciples in acts just before Pentecost. After the indwelling of the spirit’s it led the disciples to preach God’s truth in a powerful and accurate way changing many lives. This gospel changed lives in turn evangelized the known world and are still having influence today.
First: The snake was placed on a wooden stake so the people could be healed from a physical sickness caused by sin in the Exodus from Egypt.
Second: Jesus Christ was placed on a wooden stake a.k.a. the cross and lifted up as a snake/sinner to permanently heal people from the deadly sin that entered into the world in the fall of man. This not only heals the person but introduces them to eternal life and separates them from eternal death to all willing to accept God’s gift, the Gospel. Jesus, who is perfect, without sin, became the snake as He took on all our sins that we might have the opportunity to live with God in heaven.
First: Offerings and sacrifices, from Adam to John the Baptist, they were incomplete and only gave symbolic coverings to the sin that kills us.
Second: Jesus Christ came and offered himself in our place that sin can no longer have power and dominion over us. This ended all sacrifices and offerings to please a God that was unseen. The Gospel offered both the Jew and the Gentile a new way to interact with God that was full of grace, recorded in the New Testament. The gospel called both the Jew and the Greek to see themselves as totally deprived; fulfilling what was needed to people’s entrance into heaven. But the Gospel is offered as a singular solution to this impossible to be solved with man’s ingenuity Spirit problem.
There are many more. Will you tell me your firsts and seconds I missed?