As outlined in the Constitution, we are endowed by our creator with the unalienable right to life, liberty, and the pursuit of happiness.
The State of NJ requires a very strict "justifiable need" to protect your own life in public. In order to carry a self defense weapon, you must first suffer an attack, or have threats made against your life. This is similar to not being allowed to carry a rain coat because it is not raining at the moment.
The state will not clearly define what this justifiable need is, but general self defense, and the 2nd Amendment is not enough to grant a permit. Meanwhile over 40 other states enjoy this very same freedom.
Since the police do not have a duty to protect you (Warren vs District of Columbia) we are on our own for protection.