When does this eternal life begin, what does God say?

According to the testimony of the Bible, there are only two kinds of eternal existence: eternal life or eternal loss. Therefore, according to Heinrich Kemner, the greatest loss is to live and die without Jesus. John 3:15 emphasizes that “everyone who believes in him has eternal life”. The appropriation of eternal life does not occur only after death, but applies from the moment of conversion: “Everyone who believes in the Son has eternal life” (John 3:36). This faith bears the seal of the resurrection of Jesus from the dead and therefore stands on an absolute and immutable basis. God wants us to have a certainty: “These things I have written to you who believe in the name of the Son of God, that you may know that you have eternal life” (1 John 5:13).