John, the gospel writer known as the beloved apostle, writes three epistles to the Gentiles to assure them of eternal life based on his eyewitness account. John touches on light, truth, and love throughout his writing and affirms the truth of who Jesus is. John advises to "test the spirits" in order to discern false teachers and make sure they are from God. The real Spirit, the Holy Spirit, will keep with God's Word, exalt the person and work of Christ, and it will be affirmed by God's people.