Chapter five continues the themes of obeying God’s commandments and loving one another on the basis of God’s love for us (1 John 5:1-4). Adding to this, John introduced the concept of the opposing world system. This system, he declared, wholly “lies in the power of the evil one” (1 John 5:19). This is not cause for alarm, however, because our faith “is the conquering power that has conquered the world” (1 John 5:4). John had written earlier that Jesus came “to destroy the works of the devil” (1 John 3:8), so we have no need to fear him or his world, “because everyone who has been fathered by God conquers the world” (1 John 5:4), and “the evil one cannot touch him” (1 John 5:18). Instead, we can rely completely on Christ’s promise, namely that “God has given us eternal life, and this life is in his Son” (1 John 5:11). In fact, this was John’s final major reason for writing: “that you may know that you have eternal life” (1 John 5:13).
The final section includes three parts. First, John quoted Jesus’ words from John 15:7. When we are remaining in him, we can ask anything in his will, and it will be granted (1 John 5:14-15). These requests and answers are proof that we are remaining close to him. Second, there will be some who leave the fellowship because of unrepentance. Rather than bearing fruit (John 15:1-8), their sin brings them down, even to death (1 John 5:16-17). Third, once we acknowledge the only true God, anything that takes his place in our value system in an idol. “Little children guard yourselves from idols” (1 John 5:20-21).