“For God did not send his Son into the world to condemn the world, but to save the world through him.” (3.17)
“For I did not come to judge the world, but to save the world.” (12.47)
“We know that this man really is the Saviour of the world.” (4.42) (the testimony of the Samaritans)
As the third Passover of John’s Gospel draws nearer, the tension mounts until, having been prepared for His burial by Mary’s anointing Him with oil and having entered into Jerusalem as the king on the donkey, the arrival of some Greeks seeking to meet Him moves Jesus to declare that “the hour has come for the Son of Man to be glorified” (12.23) and “now is the time for judgment on this world; now the prince of this world will be driven out.” (12.31) Now is the time for Jesus to die (12.24, 33) and this is the reason why Jesus came (12.27).
He is the atoning sacrifice for our sins, and not only for ours but also for the sins of the whole world. (2.2)This is how we know what love is: Jesus laid down his life for us (3.16)This is love: not that we loved God, but that he loved us and sent his son as an atoning sacrifice for our sins. (4.10)
Because it is an atoning sacrifice that deals with sin, Jesus’ death brings life. The goal of salvation, or what we are saved into or for is life or eternal life. John’s gospel, like a coral reef or estuary, is teeming with life! In Him (the Word) was life (1.4). Whoever believes in Him has eternal life (3.15, 16, 36). Whoever drinks the water offered by Jesus “will become a spring of water welling up to eternal life” (4.13). The Son gives life to whom he is pleased to give it (5.21). He is the bread of heaven that gives life to the world. (6.33) He has come that his sheep may have life, and have it to the full. (10.10) He is the resurrection and the life: anyone who believes in Him will live, even though they die; and whoever lives by believing in him will never die. (11.25-26) And these represent only a selection of relevant texts.
Carson, D.A. (1991) The Gospel According to John (Leicester: IVP)
Kruse, C.G. (2000) The Letters of John (Leicester: Apollos)
Marshall, I.H. (2004) New Testament Theology: Many Witnesses, One Gospel (Downers Grove, Illinois: IVP)
 We could add here, the link between sin and the devil in 1 John 3.8-10: “the one who does what is sinful is of the devil” while “the reason the Son of God appeared was to destroy the devil’s work.”
 cf. Marshall p.512-3, Carson p.94
 in contrast to the previous passover when the crowd tried to make Jesus king by force, not understanding that his kingship was to be exercised by giving his life for the world (ch. 6)
 According to Kruse (pp.35, 174-178) the references to blood in 1 John 5.6-7 also refer to the atoning sacrifice of Jesus’ death.
 Marshall p.519, fn 40