Can The Redeemed Spirit Sin?

The following is reported to be true, though I cannot verify its
source:

A lawyer defending a man accused of burglary tried this creative
defense: "My client merely inserted his arm into the window and
removed a few trifling articles. His arm is not himself, and I
fail to see how you can punish the whole individual for an
offense committed by his limb."  The judge replied, "Using your
logic, I sentence the defendant's arm to one year's imprisonment.
He can accompany it or not, as he chooses."  The defendant
smiled.  With his lawyer's assistance he detached his artificial
limb, laid it on the bench, and walked out.

A. The judge accepted a faulty argument, and it backfired on him.
   1. The truth is: "One is responsible for what his arm does,
      where his feet go, and what his mouth says."
B. In answer to the question, "Can a child of God so sin as to be
   eternally lost?" people sometimes misuse Scripture by saying, 
   "The body sins, but the redeemed spirit cannot sin."
   1. The proof text is 1 John 3:9.
      a. This verse can only mean that the Christian cannot      
         continually, habitually live in sin.
      b. John had previously said - 1 John 1:8,10.
C. When Christians sin, it is not just their bodies that sin.
   1. The body is only the servant of the spirit and does only as
      the spirit directs it. Rom. 6:12-13
   2. Who does the letting and the presenting? One's spirit.
D. One's spirit is the source of sin. Matt. 15:19; James 1:13-16
E. The Christian who allows lust to conceive, and does not      
   repent, confess, and pray for God's forgiveness, will be lost 
   eternally. Acts 8:21-23; 1 John 1:9
F. When one stands before the Great Judge, he cannot use the
   argument that it wasn't me who sinned, but my body. 2 Cor.    
   5:9-10
   1. Let us cleanse ourselves of all defilement of the flesh and
      spirit perfecting holiness.  2 Cor. 7:1; 1 Cor. 6:19-20