The following audio clip is a gripping illustration given by John Piper. He is speaking of the common yet naive perspective toward the dangers of clinging to habitual sin. The gist of the entire sermon is this: to remain unrepentant in this age means remaining unforgiven, both in this age and the age to come–and there will be no opportunity for repentance in the age to come.
[Excerpt (1 min 36 sec) from Beyond Forgiveness: Blasphemy Against the Spirit by John Piper, 1984-04-01.]
My dad told this story… when I was a little boy, and scared the hell out of me. I’ve never forgotten it…
–John Piper

Interesting- I find there are so many nuances within this stern, and very frightening, message and illustration.
What I always like to point out to young believers about messages like this, is that it does not mean we should nervously question our salvation, but rather test if that salvation was real in the first place. A true believer is constantly striving toward sanctification, and testing the patience of the Father is hardly a Christlike attitude. It’s a good reminder for believers to stay on course and be serious about their faith.
Of course, messages like this continue to challenge me in my views of Lordship Salvation. I believe every Christian should agree on the principle, but it is easy to see why there is so much disagreement over the particulars.