I must thank Elad for pointing me in the direction of an excellent article on self-defense.
The short of the article is:
Though we see sanction and even a qualified directive from Christ to possess personal weapons, we must remember three points. First, in the remainder of the New Testament, we have no further examples of believers taking up the sword. Secondly, the emphasis in the remainder of the New Testament is decidedlynot geared toward the issues of physical self-defense or righteous use of lethal force. Rather, we see more emphasis on Godly living, suffering affliction and persecution for Christ, and grasping the precious doctrines of Christ and the Gospel. Thirdly, possession of weapons and acquiring the skill to use them in self-defense is permitted but not required by Scripture.