When you’re born again, your spirit is made new. It’s alive in Christ Jesus. Even though there is no outward change, your spirit has become a new baby. God’s baby, responding to God’s voice. Your body however, does not change. Unless God intervenes supernaturally (and He sometimes does) your body still has all its old habits and peculiarities, and finds it easier to respond to other voices – like the voice of the world or the voice of the devil, than to the Voice of God.