The verse 1 John 4:9 states: “In this the love of God was made manifest among us, that God sent his only Son into the world, so that we might live through him” (ESV). This verse is part of a broader discourse on the nature of God’s love and how it is expressed through Jesus Christ.

From an evangelical Christian perspective, the Apostle John is traditionally regarded as the author of the book of 1 John, as well as the Gospel of John and the book of Revelation. John is often identified as the “beloved disciple,” who had a close relationship with Jesus during His earthly ministry.

### Background on the Author:

1. **Apostolic Authority**: John was one of the twelve apostles, and he is often recognized as the only one not to have died a martyr’s death. Evangelicals appreciate John’s firsthand experiences with Christ and the authority he brings to his writings.

2. **Themes of Love and Truth**: The epistles of John, including 1 John, emphasize the themes of love, truth, and the divinity of Christ. John writes extensively about the nature of God as love and how believers are called to love one another in response to God’s love.

3. **Context of the Writing**: 1 John is believed to have been written in the latter part of the first century, likely addressing early Christian communities that were grappling with various theological issues, including the nature of Christ and the challenge of false teaching. The emphasis on love is seen as crucial in countering these heresies and reinforcing the Christian community’s identity.

4. **Evangelical Perspective on Love**: Evangelicals hold that John’s emphasis on God’s love culminates in the sacrificial act of Jesus Christ, reinforcing the doctrine of the atonement and the redemptive nature of God’s love. The belief that God sent His only Son is fundamental in evangelical theology, affirming the centrality of Jesus in salvation.

5. **Pastoral Intent**: The writing style and content of 1 John exhibit a pastoral intent, as John aims to encourage and edify believers, assuring them of their salvation and urging them to live out their faith in love and obedience.

Overall, 1 John 4:9 is significant in evangelical theology as it encapsulates key doctrines about God’s nature and Jesus’ mission, emphasizing the relational aspect of faith and how it shapes the believer’s life and actions.