13 My purpose in writing is simply this: that you who believe in God's Son will know beyond the shadow of a doubt that you have eternal life, the reality and not the illusion. And how bold and free we then become in his presence, freely asking according to his will, sure that he's listening. And if we're confident that he's listening, we know that what we've asked for is as good as ours.
16 For instance, if we see a Christian believer sinning (clearly I'm not talking about those who make a practice of sin in a way that is "fatal," leading to eternal death), we ask for God's help and he gladly gives it, gives life to the sinner whose sin is not fatal. There is such a thing as a fatal sin, and I'm not urging you to pray about that. Everything we do wrong is sin, but not all sin is fatal.
18 We know that none of the God-begotten makes a practice of sin - fatal sin. The God-begotten are also the God-protected. The Evil One can't lay a hand on them. We know that we are held firm by God; it's only the people of the world who continue in the grip of the Evil One. And we know that the Son of God came so we could recognize and understand the truth of God - what a gift! - and we are living in the Truth itself, in God's Son, Jesus Christ. This Jesus is both True God and Real Life. Dear children, be on guard against all clever facsimiles.