The most-likely author of 1 John 4:20-21 is the apostle John, who is also traditionally believed to be the author of the Gospel of John and the book of Revelation. He was one of Jesus’ original 12 disciples and played a prominent role in the early Christian church.

From an evangelical Christian perspective, John is often seen as a key figure in spreading the message of Jesus and the teachings of the early church. He is known for his emphasis on love and for his close relationship with Jesus, being often referred to as the “disciple whom Jesus loved.”

In 1 John 4:20-21, John emphasizes the importance of love for God and love for others. The passage reads, “If anyone says, ‘I love God,’ and hates his brother, he is a liar; for he who does not love his brother whom he has seen cannot love God whom he has not seen. And this commandment we have from him: whoever loves God must also love his brother.”

Evangelical Christians regard these verses as a powerful reminder of the inseparable connection between love for God and love for one’s fellow human beings. They see John’s writing as a call to authentic, selfless love as a central aspect of the Christian faith.