Through the new technology, Jake is allowed to act within a healthy Na'vi body and enter the world that mere humans cannot access. The man once broken and "sullied" by our world is given new life - aptly - by Dr. "Grace." It is through his new avatar that Jake truly begins to learn what it is to live.
Interesting, from a Christian point of view, for it is we who are also sullied by sin; and it is grace that brings us back and gives us new life. Along with that come the Gifts of the Holy Spirit: wisdom, understanding, knowledge, piety, counsel, fortitude (or courage), and fear of the Lord. Jake Sully exhibits these new noble qualities as he begins to accept the ways and outlook of the Na'vi people. They are in harmony with their surroundings and with one another - almost utopian. This sort of right relationship is the goal of Christian - and human - life. We are all called to the sense of justice that sees the connections between all - and above all, with God. This is the fruit of Grace, and it brings us out of ourselves to discover ourselves anew.