parable

Abaya, you said

"But wouldn't you at least agree that some kind of steady discipline of the self/body/thoughts is necessary, for at least *trying* to grow closer to Christ..."

Perhaps the steady discipline is fellowship with other believers with whom you are accountable, so they may encourage and support you in your walk. Also, if you endeavor to serve the purposes that God has in mind for you, you realize that you need His help to do those things. So, its important not to hinder your relationship with God by indulging things that alienate you from Him. I am convinced that temptation can only be resisted if there is a more appealing choice to be embraced. Otherwise, its inevitable because no one can simply resist something forever, there must be a proactive choice to do something else. For me, preserving a clean conscience is fundamental to being open to the blessings that God has for me and for others through me, and that is what I try to remember when I struggle with temptation. I believe this is what scripture is talking about when it promises that with every temptation, there is always a way out, a choice for something else.

You said

"What puzzles and frustrates me, however, is when Christians place themselves right in the middle of temptation to sin, not even *trying* (very hard) to avoid the things that would cause them and others to stumble. They are not fleeing from temptation; they are running headlong into it. I find this kind of behavior very difficult to understand."

I believe it is understandable as a failure to have alternatives in mind that are more appealing. It takes an honest person to admit that temptation is all about selfishness. In my experience, the process of becoming more Chist-like is characterized by becoming less attached to selfishness, liberated from the constraints of having it be about me all the time.

You asked, "does Piper say it's alright to look at pornography?"

I don't think so. Piper's thesis is that our natural desires were placed within us to drive us to God, because they remain unfulfilled so long as we attempt to satisfy them with things other than God. As CS Lewis once said

"If I find in myself a desire which no experience in this world can satisfy, the most probable explanation is that I was made for another world."

As for porn, here's my view:

See pornography.
See those who have been used to produce it.
See humiliation and degradation.
See in them the opportunity for compassion and love.

See pornography.
See those who profit from it.
See perversion and greed.
See in them the wicked desire to lead others into addiction.

See pornography.
See those who have been seduced by it.
See self-loathing, isolation and dispair.
See in them their secret shame.

See pornography.
See those who have lost a loved one to it.
See heartache.
See in them the pain of betrayal.

See pornography.
See those who help in recovery from it.
See dedication, training and experience.
See in them a promise of freedom.

See pornography.
See those who fight against it.
See courage to take a stand.
See in them a hope to overcome.

See pornography.
See the alternative.
Choose.

Parable