Yes Harry is going to have to mature a lot more and also become a lot more powerful wizard in order to take on Voldie, even him as a mortal, by judging Harrys powers at the end of book 6, he won't even be close enough to take on Voldie... I'm guessing in book 7 that he matures a lot, and learns a lot more powerful magic than just what they teach at Hogwarts, maybe he will discover who this R.A.B Character is and he will help him, because he said it was his quest to make Voldemort Mortal for when he meets his final match, which is Harry.. Only Time will tell these answers