Isn't that a recipe for near Universalism? I don't know if Walls believes in retroactive answers to prayer, but that combined with his view of grace and his flirtation with purgatory and postmortem evangelism would imply that God could save people regardless of their faith in Christ all the way back to Adam. So, long as someone had loved them at some point in their lives (which is nearly everyone). For example, John Doe prays for his deceased parents who died as unbelievers. If God loves John, and John loves his parents, then God MUST save John's parents. Since John's parents lovedtheir unbelieving parents, then God must save John's grandparents. All the way back to Adam. But what if John's maternal grandmother hated her father at her death? Well, if God saved her, then divine love working in her heart would change her attitude toward her father and he would eventually be saved by her retroactive prayers too! So that he's snatched out of hell like she was. If Walls gave up purgatory, then maybe no one even enters hell since God (presuming Walls believes God is timeless) could answer prayers retroactively such that nearly everyone is saved upon death due to the backward causation of retroactive prayers.BTW, I'm sure some genuine Satanists have had affection for the demons they worshipped on earth. In which case, God must save them too. Those demons also likely had affection toward the other demons before they all fell. Which implies all demons will end up being saved so long as they all knew each other before the fall.
A miscarried zygote may not have been loved because he/she wasn't known to have existed, but it's easy to imagine all the saved in heaven conferring with each other and agreeing to pray for all miscarried children that they had. Since, if they knew they existed they would now love them now that they are in heaven.
BTW, I'm open to the possibility of God answering retroactive prayers. But not to the extent above.
Re-reading my comments, I realize I didn't need to invoke retroactive prayers until the last hypothetical where people don't even go to hell or purgatory. In Walls view, even without retroactive prayers, someone could potentially be released from hell or purgatory if his principle of God having to love everyone that we love were carried out consistently.
There are people who love and worship Satan.
Well, the answer to that was pretty obvious. Do I win a prize? ;)