We accept human testimony, but God’s testimony is greater because it is the testimony of God, which he has given about his Son. 10 Whoever believes in the Son of God accepts this testimony. Whoever does not believe God has made him out to be a liar, because they have not believed the testimony God has given about his Son. 11 And this is the testimony: God has given us eternal life, and this life is in his Son. 12 Whoever has the Son has life; whoever does not have the Son of God does not have life.13 I write these things to you who believe in the name of the Son of God so that you may know that you have eternal life. 1John 5:9-13
Remember the transfiguration? Peter, James and John go up a mountain with Jesus, and like in a scene from Cocoon, Jesus temporarily "unzips" his skin and bright light glory like the kind that fried Saul's eyes on the road to Damascus, like the kind that left Moses glowing for weeks after Mt. Sinai emanated from Jesus. Elijah and Moses appear and a voice from God echoes, "This is my Son. Listen to Him." Jesus, now not glowing and Moses and Elijah going back to I figure Abraham's bosom now for a very short time, descends down the mountain with them and tells them not to tell anyone what they had seen until after the resurrection.
Here it is, much after the resurrection, now knowing and believing what Jesus meant by "rising from the dead" and he gets to tell about it. Peter had previously told about it in his second epistle;
" For we did not follow cleverly devised stories when we told you about the coming of our Lord Jesus Christ in power, but we were eyewitnesses of his majesty. He received honor and glory from God the Father when the voice came to him from the Majestic Glory, saying, “This is my Son, whom I love; with him I am well pleased.” We ourselves heard this voice that came from heaven when we were with him on the sacred mountain. We also have the prophetic message as something completely reliable, and you will do well to pay attention to it, as to a light shining in a dark place, until the day dawns and the morning star rises in your hearts"
John says basically that he is testifying that Jesus is God's son and savior of the world but if people don't believe his word, trust God's word who testified at His baptism and also at the Mount of Transfiguration. John was also the only disciple at the cross where the light went away in the middle of the day and the ground shook and the soldier who stood there believed from all that transpired.
Believing this testimony that God sent His Son to die on the cross for our sins and raised Him to give eternal life is what is necessary to be forgiven of our sins, receive the Spirit who gives us life and a deposit guaranteeing eternal life in Heaven. Rejecting that doesn't send us to hell, we were already on our way to Hell. Jesus is sent as a lifeline to deliver us.
When you ask someone if they are going to Heaven when they die and they say, "I hope so.", it pretty much means they aren't. If you think someone is arrogant when they say that they are going to Heaven someday, it also shows that you don't understand salvation. By faith, believing and receiving God's free gift of salvation, and not our good deeds, is what saves us and John says that he writes these things so that you can know for certain you are going to Heaven someday. That's why I don't need to fear death. That's why I can humbly say that I'm for certain going to Heaven when I die. What about you? Do you know for certain you are going to Heaven when you die? You can! And don't just take John's word for it - take the creator of the universe's word for it, the one who is eternal life and created Heaven. I'll believe Him!
