not all is forgiven

And furthermore, when it comes to the God of the Bible there is only one kind of sin in the world--forgiven sin.
Chalke and Mann, the lost message of Jesus, p. 109

This quote comes in a context of the writer writing about the parable of the prodigal son. Is the statement true, though? Is it true there is only forgiven sin in the world?

Forgiveness rests basically, then, on the atoning work of Christ. That is to say, it is an act of sheer grace. 'He is faithful and ust, and will forgive our sins' (1 Jn 1:9). On man's side repentance is insisted upon again and again. John the Baptist preached 'a baptism of repentance for the forgiveness of sins' (Mk 1:4), a theme which is taken up by Peter with reference to Christian baptism (Acts 2:38). Christ himself directed that 'repentence and forgiveness of sins should be preached in his name' (Lk 24:47). Forgiveness is similarly linked with faith (Acts 10:43, Jas. 5:15). Faith and repentence are not to be thought of as merits whereby we deserve forgiveness. Rather they are the means whereby we appropriate the grace of God
New Bible Dictionary 2nd Edition, p. 391

Something should not be believe simply because it is nice-soundin; if anything, the "too good to be true" reaction is probably a good sign that what one is hearing is not true, not to mention that it may be a scam or fleece.

Chalke's quote above has no scriptural support to it, not even in the context of the prodigal son parable. And in fact, one can find scriptures where even Jesus those who are opposing Him that they will die in their sins (John 8:21-24, reference found in 'What the Bible Teachers' by RA Torrey, p. 358).

There may be a wish that all people should be forgiven, but the wish doesn't make it so. Forgiveness of sin seems closely linked in the Bible to repentence and faith, and is not an isolated thing forced on people ("Your sins are forgiven, I don't care how you feel about it, so deal with it.")