Destiny is something that has been (and probably will be) debated. I'll give you the sun has shown destiny in a way I don't recall ever seeing it presented. Not as some linear thing but a ball of yarn thrown out on the ground. A chance encounter Jude has with an attractive English guy can turn out to be the man that Noah had drawn years ago because that was part of her destiny. Her new teacher could be the same man that her mom knew without either of them knowing. Everything is connected but never in the way you think it would be.
This book also shows excellently that its okay to just be you. One of the main characters in this book, Noah, is gay. This isn't pointed out in this book like its a  huge deal or something horribly abnormal. Its just okay. And I love that. While it does cause some problems between him and his sister they do an excellent job of not making his sexuality that bad guy.
Lastly, sometimes things don't turn out the way you thought they would. Noah saw his mom doing something she shouldnt. He realized that she was going out late to do it every evening. He knew that was what was messing with their marriage. But he could have never ever predicted the impact that would have on Jude years later as her teacher. Everything comes full circle and this is surely no exception.
Over all, this book is wonderful and I totally recommend reading it. Its basically the best.