What does John 15:8 mean?
During His earthly ministry, Jesus' actions often inspired others to glorify God the Father (Matthew 9:8; Luke 17:15–16; John 11:4). He also made it clear that He acted only according to the will of God the Father (John 5:19; Matthew 26:39). When God's people depend on His Word (John 15:7), and obey His will, He is glorified in it. This is not only the ultimate point of our service to Him, it is also proof for ourselves and others that we are truly born again.The sequence Jesus uses here is important for our understanding of salvation. He does not say, "when you obey, you are saved." He does not say, "when you bear fruit, that earns you the status of disciple." Christ specifically says that bearing spiritual fruit is evidence of one's relationship to Him. This is an important point when looking at Scriptures such as James 2:14–17. There, James says the same thing as Jesus, but with a different perspective. Good works, and spiritual fruit, are evidence of one's salvation—not something one pays in order to buy it.
In the prior verse, Jesus pointed out that prayers from one "abiding in" Christ, in whom His words also "abide," are aligned with the will of God and therefore guaranteed. It is His power and His will that make these things possible. Without a true connection to Christ, spiritual fruit cannot be produced (John 15:5). Merely pretending to have eternal life doesn't result in spiritual abundance, or salvation (Matthew 7:21–23; John 15:6).