Summary of Chapter 15
The 15th 'lie' that Young reacts to is that 'hell is separation from God'. Young starts out by saying that he grew up in a fear-based version of faith. One became a Christian to avoid hell (viewed as eternal conscious torment). Young now knows that there are actually 3 'Christian' views of hell (eternal torment, annihiliation, redemptive). In this chapter, however, he simply aims to address the lie in the title. Young insists that, while we can reject or ignore it, we do not have the power to separate ourselves from the love of God. In Hell (as on earth) we may experience a 'sense' of separation, but we are never actually separated from the love of God. That's impossible. The 'fires' of hell serve the loving purpose of burning away 'every vistage of evil and darkness that prevents us from being fully free and fully alive'. Hell is a place of purification, not punishment.
I am glad Young brought up the 3 'Christian' views of hell. I, too, believe that each of these views fit within broader Christian orthodoxy (Hell was the subject of my Master's Thesis). Additionally, I think Young's point in this chapter (that hell is not technically separation from God) is a good one. God's character doesn't change after we die, nor does God's omnipresence meet its borders. No objections here.
This chapter also sheds some more light on what was said in chapter 13. It seems that Young believes hell is an 'age of redemptive purification' (the 3rd view). So, from his perspective, all who die not yet having experienced their pre-existing salvation (still ignorant of it or rejecting it) will be confronted with the fiery love of God which will burn away (so to speak, I doubt Young interprets this literally) our ignorance and rejection of God. All will experience God's love and be saved. As I said, I do not consider this 3rd view (which I refer to as 'eventual restoration' to be heretical. My own view would include the possibility of postmortem redemption (with Young), but not the certainty of it (against Young).