What does John 17:20 mean?
In the earlier portion of this High Priestly Prayer, Jesus made requests on His own behalf (John 17:1–5). Next, He prayed for those God had given Him out of the world (John 17:6–19). In the most immediate context, this meant the inner circle of disciples. However, many of those ideas also apply to Christians living in the world today, as this verse implies. Here, Jesus begins explicitly praying for the spiritual well-being of those who will come to faith through the ministry of the apostles.The "word" which these men will utilize is the overall message of God. That includes the person and ministry of Jesus Christ (John 1:1), His teachings (John 14:26; Matthew 28:19–20), and the written messages the apostles will record (2 Timothy 3:16). Just as God the Son—Jesus—was sent into the world to proclaim a message from God the Father (John 10:36–38; 17:6–8), so too are Christian believers sent into the world to proclaim a message given to us by Christ (John 17:18).
A major theme of this prayer, seen expressed in the next verses, is an appeal for unity expressed in Christian love (John 17:26).