I'd appreciate feedback from professing Christians. It gives me pause to disagree with Piper. I agree with some of what he says. Some of it I almost see as sinful in the right context and disagree sharply.
I am a professing Christian (despite the fact that some in Christianity would claim I am not really a Christian).
Let us start by recognizing that "Christianity" is a rather broad umbrella with a lot of different social views. There are Christian denominations that are either pacifist or that have a large number of members who are pacifists. I would not wish to disparage such sincerely held beliefs. I believe that pacifism can be consistent with Christian teachings and beliefs...but probably only as a personal obligation between an individual and God. For example: some may find themselves unable to use defensive violence without crossing into hate or other forbidden attitudes. For them, "plucking out" the eye that offends them, as it were, may be the best option to remain true to the dictates of their Christianity.
But for most Christians I believe that self-defense against unjust aggression is in keeping with Biblical teachings. What Piper has done in this paper is to focus on scriptures that support his point of view while ignoring scriptures that may counter his preconceived notions. This is common. We often see the non-religious attempt to beat Christians into submission on social issues by claiming that Jesus said we must love everyone (true) and then equating disagreement with behavior or honest preaching/teaching about what is sinful as being "hateful" (of course that is not what hate is). Among the religious, it is common to focus on scriptures that support our points of view or religious doctrines, while downplaying, ignoring, or re-interpreting scriptures that otherwise contradict us.
The Bible is full of seeming contradictions including the contradiction between "let your light so shine" to the "don't let your left hand know what your right hand is doing".
As I posted in the
Liberty University thread about the address to which Piper is responding in the article you reference, Christ didn't much chastise or correct Peter for cutting off the Centurian's ear. He merely corrected Peter in that moment, and healed the ear, which removed all evidence of Peter committing a capital crime, leaving Peter free to continue his earthly ministry. He made clear that it was within His power to call down legions of angels to protect Himself if that were part of God's plan for Him. Since it wasn't, He didn't. That doesn't mean that rank-and-file Christians should plan to be defenseless victims, generally.
The same Jesus who Piper and other quote as being a pacifist, violently cleansed the Temple not once, but twice in recorded accounts. He cursed unto death an Olive Tree who gave the appearance of having fruit ready to eat, but that upon closer inspection was barren. Jesus Christ was not nearly the one-dimensional, pacifist some try to make him out to be.
I believe that Christians have an obligation to believe Jesus is the Son of God, the promised Messiah, their Savior and Redeemer, and to rely upon His grace for a remission of our sins. We have an obligation to love God and to love our fellow man as ourselves. We do not have any obligation beyond that when it comes to immigration, taxes, self-defense, UFOs, or most other social and political issues. I believe we should show respect to those whose personal understanding of Christianity or their personal obligations to God require them to adopt any particular social or political position. I don't believe such understandings on the part of others impose an obligation on the rest of us.
An internet search turns up several articles on the topic of Biblical teachings and self defense for those who want to do some study:
http://www.biblicalselfdefense.com/ (a nice study of pro-self-defense biblical scriptures from both the Old and New Testaments)
http://www.vatican.va/archive/ccc_css/archive/catechism/p3s2c2a5.htm (Catholic catechisms including dealing with self-defense)
http://www.ldsliberty.org/the-right-and-responsibility-of-self-defense/ (one lay-member's view of Mormon teachings on self-defense)
Charles