The Gospels, which mark the beginning of the New Testament, are composed of four books: Matthew, Mark, Luke, and John.
The first thing we must keep in mind when reading the Gospels is that they are not separate stories from the Old Testament.
Rather, the Gospels are a continuation and fulfillment of the Old Testament.
The Gospels represent the culmination of God's work with His people and the fulfillment of the covenant He gave to Moses and the prophets.

---From "Page 32, Chapter 1, Gospel 1"

What we must realize through the Transfiguration incident is the true glory of the Holy One, Jesus Christ, which shines even in the face of the suffering that will come.
Here too, the voice of God the Father is heard.
“This is my beloved Son; listen to him” (Mark 9:7).
These words confirm that Jesus is the Son of God despite the sufferings that are to come.
The Transfiguration incident is a significant event that reveals the true glory of the Son of God before His suffering.
The splendidly transformed appearance of Jesus enables us to look forward to the glory of the resurrection and to foretaste the coming kingdom of God in glory.

---From "Page 85, Chapter 2, Gospel 2"

The suffering and death of Jesus are central to his ministry.
Jesus had already taught his disciples several times that he would suffer and die.
The disciples could not understand Jesus' words at all.
A week before his crucifixion, Jesus enters Jerusalem riding on a donkey.
And around the temple, he taught with many parables and lessons, and showed that he was the true temple.
Jesus shares his last meal with his disciples and establishes a new covenant that surpasses all previous covenants.

---From "Page 98, Chapter 3, Gospel 3"

Throughout church history, the four Gospels have always been understood as belonging to the same genre.
Of these, the Gospels of Matthew, Mark, and Luke are called the 'Synoptic Gospels'.
Meanwhile, as you read the Gospel of John, you will find that this gospel is a little different from the Synoptic Gospels.
John, one of the three disciples who were closest to Jesus personally, explains in detail what the Kingdom of God means for our lives, talking about how Jesus' coming gives us "life" rather than using the term "Kingdom of God," which appears frequently in the Synoptic Gospels.

---From "Page 132, Chapter 4, Gospel 4"

The suffering, death, resurrection, and ascension of Jesus are central events not only in the Gospels but also in the Acts of the Apostles.
The Acts of the Apostles is a sequel to the Gospel of Luke, written by Luke, and shows how the disciples left behind after Jesus' ascension expanded the gospel.
And the central theme of all these stories is the 'Pentecost descent of the Holy Spirit', which is not simply a partial event that reveals God's power and authority, but rather an important event that occupies a very central position in God's history of salvation.
The bold preaching of the gospel by the disciples after the descent of the Holy Spirit on Pentecost is clearly reflected in the sermons they delivered.
In particular, the sermons of Peter and Stephen confirm that Christ's death, resurrection, and the descent of the Holy Spirit are not merely symbols of a new era, but also the fulfillment of God's plan of salvation promised in the Old Testament and events predetermined by God.

---From "Page 168, Chapter 5, Acts 1"

Through Paul's life and preaching, we see how God strives to save His people.
We also see that the churches that Paul established through his missionary journeys, although weak at first, grew steadily over time.
Paul was a missionary who preached the gospel vigorously even in difficult situations and followed the heart of God who did not rest until all people were saved.
Through Paul's ministry, we can learn what a holy calling is and what true gospel passion is.

---From "Page 204, Chapter 6, Acts 2"

Sinful human beings seek to attain righteousness through their own merits and the law.
But man can never save himself.
God sends a new righteousness to these people, Jesus Christ.
Jesus, who came to save sinners, offers salvation, a gift from God, to all believers without discrimination.
In this context, Romans emphasizes that Abraham, who was justified by faith in God, is not only the “father of the Jews,” but also the “father of all Gentiles,” who are justified by faith.

---From "Pages 264-265, Chapter 7, Romans"