And the witness is this: that God has given us eternal life, and this life is in his son. He who has the son has the life; he who does not have the son of God does not have life. These things I have written to you who believe in the name of the son of God, in order that you may know that you have eternal life.

1 John 5.11-13

• believing Jesus is the son of God
  If you don't believe Jesus is the son of God, he says, you make God out to be a liar. Ouch!
• overcoming the world
  Who is it that overcomes the world? Only he who believes that Jesus is the Son of God. - 1 John 5.5

  Now that's good news. Overcoming the world - with its temptations and distractions - that sounds really good to me. Because most of the time I don't feel like I've overcome the world; I feel like I'm just staying afloat. Maybe the thing is to recognize that, as he says, we have indeed overcome the world, and not feel and act defeated?

• eternal life.
  And as an old friend (who'd object to being characterized that way) said, "Eternal life begins now." The other thing is that eternal life is secure. If you had it only for a couple of years, it wasn't eternal at all, was it?