1. We have placed our hopes for heaven entirely on Jesus. (1 John 5:13)
The gospel, by its very nature, produces assurance. Because the gospel proclaims “Jesus in my place,” my assurance does not depend on how well or how much I have done. It depends on whether or not I rest in his finished work. So the question is not, “Can I remember praying a prayer?” or “Was my conversion experience really emotional?” The important question is, “Are you currently resting on Jesus as the payment for your sin?”
2. You have a new nature. (vv. 16–18)
If you have been born of God you have been given a new nature. And that comes with new desires. So you do not “keep on sinning,” as John writes, because you have new desires. As an earthy way to think about this, you might imagine some vomit on the ground. None of us would require a list of rules keeping us from eating it. Why? Because we find it disgusting. Now, a dog has a totally different nature, with different desires. A dog would find that vomit as appetizing as we find it disgusting.
This is how God changes us: not by browbeating us with rules, but by giving us a new heart. You no longer love dishonesty and hatefulness and immorality like you used to. You do not avoid them because of threats from God, but because these things start to make you sick.