This really is such an amazing passage, there is so much here to take in:
For God so loved the world that he gave his only Son, so that everyone who believes in him may not perish but may have eternal life. Indeed, God did not send the Son into the world to condemn the world, but in order that the world might be saved through him. Those who believe in him are not condemned; but those who do not believe are condemned already, because they have not believed in the name of the only Son of God. And this is the judgment, that the light has come into the world, and people loved darkness rather than light because their deeds were evil. For all who do evil hate the light and do not come to the light, so that their deeds may not be exposed. But those who do what is true come to the light, so that it may be clearly seen that their deeds have been done in God.
While I think there can be a few different ways to go with this passage, I like to look at it from the perspective of the missio dei. I think it has much to contribute to how we know and understand the mission of God. In fact, I like to look at a lot of the Bible as a whole in the light of salvation history and missio dei. I don’t own the book but I know Howard Marshall in his NT Theology talks about how New Testament Theology is missionary theology. I think he is exactly right! And I think the whole thrust of John’s letters is missional through and through. Sure there is Christology and other issues but I would say the overall theme of the book is a missional one – it is seen in God giving his only Son, that everyone who believes in his name may not perish but have eternal life.
What is the missional focus? God so loved the world he gave his one and only Son. He sent him not to condemn, but to save.
I think the missional focus of the Fourth Gospel can be supported by the Letters of John. First John tells us,
1 John 4:9 God’s love was revealed among us in this way: God sent his only Son into the world so that we might live through him.
1 John 4:10 In this is love, not that we loved God but that he loved us and sent his Son to be the atoning sacrifice for our sins.
1 John 4:14 And we have seen and do testify that the Father has sent his Son as the Savior of the world.