I was just waiting for this. The NRSV renders this verse as "Not that I have already obtained this or have already reached the goal..." But if you really want to use a translation that renders it as "already become perfect," let's see what the KJV says three verses down: "Let us, therefore, as many as be perfect be thus minded..." (In all fairness, the NRSV renders it as "Let those of us then who are mature be of the same mind; and if you think differently about anything, this too God will reveal to you." At the same time, rendering the word as 'mature' instead of 'perfect' doesn't substantially change the meaning of things, since we understand 'perfect' in this verse to mean a 'complete' or 'full-grown' person--these are actual definitions for the word 'perfect' in English and for the term used in the Greek.) According to several commentators, the way that the Greek word rendered 'already become perfect' in v. 12 is used is as an idiom taken from sporting events, used to indicate 'completing a course,' hence the NRSV translation.
Funny, if there was any human who I would think could be "perfect" it would be the Apostle Paul.
Oh, but he does claim to be perfect: read Phil. 3:15. ;)
Throughout his epistles he continually emphasizes the Christian life as a race or battle. He makes it sound as if it were a race in which the finish line is in the near distance and yet he knows that he will not complete his perfection until he falls dead on that finish line. Here's my concern. When we decide we are perfectly sanctified do we quit the race? Is there anything left to battle? Have we accomplished all there is in this life?
Of course not. There is still temptation to fight, there is still a war going on outside--the battle's just won on the inside (assuming one keeps that state). We are able to focus more on the things of God, and God Himself, since we don't have anything within us getting in the way.
The biggest problem is, of course, now that we have declared ourselves perfect, all those less than perfect Christians. It seems the only task left for us then is to continually judge those "carnal" Christians and rebuke them for failing to acheive that perfect state.
I fail to see how that would be loving, which is exactly what a 'perfect' Christian is. Hence, I think it unreasonable to assume that a person who claimed Christian perfection and yet behaved this way was telling the truth any more than I assume that a person who calls himself a Christian is telling the truth when he doesn't live it.
Ah yes. That Wesleyian love I've heard so much about.
You sinner! You added an i to the word Wesleyan! You'll burn in hell if you don't shape up! ;P (I'm teasing.)