Although I haven't read this particular book, the idea that God is so loving that He could never send anyone to hell isn't new; it's been around for centuries. (The theological term for this idea is "universalism" -- the belief that all humanity will be saved.)
But this is not what the Bible teaches. The Bible makes it very clear that hell is real; in fact, it's just as real as heaven. You might be surprised to learn that Jesus said more about hell than anyone else in the Bible, and constantly warned us against going there. Some day, He said, God will judge the world with perfect justice. When he does, "he will say to those on his left, 'Depart from me, you who are cursed, into the eternal fire prepared for the devil and his angels'" (Matthew 25:41).
This is a sobering truth, and we should not dismiss it or take it lightly. Hell, the Bible says, is a place of eternal separation from God, and is the final destiny of all who deliberately reject God and want nothing to do with His Son. Why would anyone want to go there?
But the Bible tells us another truth: We don't have to go there! God has provided the way for our sins to be forgiven, and for us to inherit the gift of eternal life. That way is Jesus Christ, who took upon Himself the judgment we deserve. Don't be deceived, but turn to Christ and give your life to Him, for He alone has opened heaven's door for us.