Jefferson Vann shares the consequences of rejecting God’s love as explained in the context of John 3:16.
John 3:16-21 (JDV)
John 3:16 Because God cared about the world in this way: He gave his one and only Son, so that everyone faithful to him will not be destroyed but have permanent life.
John 3:17 Because God did not send his Son into the world to condemn the world, but to save the world through him.
John 3:18 Anyone faithful to him is not condemned, but anyone not faithful is already condemned, because he has not trusted in the name of the one and only Son of God.
John 3:19 This is the condemnation: The light has come into the world, and people cared about darkness rather than the light because their works were evil.
John 3:20 Because everyone doing worthless things hates the light and avoids it, so that his works may not be exposed.
John 3:21 But anyone doing the truth comes to the light, so that his works may be shown to be worked by God.”
consequences of rejecting God’s love
David Buchanan notes that John 3:16 is the most well-known verse in the Bible, but draws our attention to the fact that it is followed by “a stern warning that is sometime overlooked in light of the wonderful promise. Verses 18-20 tell of another promise that is just as sure as the first: if you refuse to believe, you are condemned to eternal death. When we share the gospel with the unsaved, we should present the love of Jesus Christ and his promise of salvation first and foremost. But to those who remain complacent, unconvinced or reluctant, we should love them enough to also warn them of the consequences of failing to accept the Lord as their Saviour.”1
The promise for those believing in Christ is permanent life. The consequences for those not believing in Christ are suffering for one’s own sins, and eventually permanent death.
For more on the two permanent destinies, see:
 David Buchanan, Maranatha Advent Christian Devotional. Saturday, February 17, 2018 (sic).