I am just loving The God Who is There, by D.A. Carson. If you're looking for a book to discuss with a young person or someone new in his faith, this is great one to use. I wish we'd had it when we were having our Sunday night bible studies with the young people.
I loved this reminder in the chapter, "The God Who Grants New Birth."
Understand this: you and I may not be able to explain all the mechanisms of new birth. From the Bible we may study passages like this one [John 3] and a handful of others that talk about new birth, and doubtless we can infer quite a few things about how this new birth works. But at the end of the day, we will not possess a full analysis of how God works powerfully within us to transform us. Nevertheless, where there is genuine new birth you always see the results. You can't deny them. "So it is with everyone born of the Spirit" ... New birth has not necessarily taken place "because somebody's made a commitment to Jesus." Where there is new birth - where it has genuinely come from God - you will see transformation. You will see change in the life. That does not mean that people have suddenly reached perfection: we shall have more Christian growth and Christian failures in due course. But where the new birth takes place, there is a change of direction, of origin. There is a cleaning up in the life. There is transformation. There is the beginning of life from God himself that shapes our existence in a new direction.
I think this transformation has to involve a lot more than moral conduct. We can be the most sympathetic, altruistic, compassionate person and still not be born again. I know people who are professed atheists who put me to shame with their good deeds. Their moral indignation over atrocities in the world are commendable, but transformation is a lot more than that. Transformation means that the object of our worship is God, and Him alone. It means casting out the idols that we don't even realize have become idols. Being right all the time, having the last word, getting my way, feeling like people owe me their approval, ignoring the sound teaching of Scripture; these are all things that are a result of my self-idolization, and if they become a problem, I must ask the question, am I born again?
People who have been born again seek the Lord. They hunger for His word like they are crawling through the desert, parched and desperate. They seek to have their existence shaped by God and His Word. A life devoted to God must involve His Word. Without the standard of His Word, we are in danger of worshiping a God of our own making, forcing Him into a mold that is more about our desires than about reality. Transformation begins with the Word, and it continues to grow as we study the Word and the Spirit renews our mind.