It is only and excerpt, the link for the entire study is at the bottom.
For our present study, I want to look at John 15:26-27 and see what the New Testament teaches about the nature of our witness--as individual members and as a total body. Our text reads as follows: “But when the Comforter is come, whom I will send to you from the Father, even the Spirit of truth, who proceedeth from the Father, He shall testify of Me; and ye also shall bear witness, because ye have been with Me from the beginning.“ As we study these two verses we’re going to discover that they contain the whole scheme of the witness of the body--all the way from God to you and everything in between.
* Court is now in session
The word “witness“ in John 15:27, is a very interesting word. It is a legal term and takes us into a courtroom scene: We see a judge on the bench and a prisoner on trial. We hear the case argued by lawyers - first the prosecution, then the defense. Both call witnesses to substantiate their cases. We, as individual members of the body, are individual witnesses in the trial. Who’s on trial? Jesus Christ. Who’s the judge? The world. Who’s the defense attorney? The Holy Spirit. Who’s the prosecution? Satan, with his lies and accusations.
As witnesses in this trial, we have two ways to witness - as individual members and as a total body:
1) As individual members
As individuals, we are separate witnesses in a situation where Jesus Christ is on trial before the world. And the world is constantly judging Christ on the basis of the witnesses. Some people judge Him to be a fake; some judge Him to be a good man; others judge Him to be a teacher; while others, a liar, and so on. Do you see how absolutely strategic your witness becomes? If your witness tears down the claims of Jesus Christ by the kind of life you live, you’d be better off if you were out of the courtroom altogether. You only confuse the issue! The devil is the prosecutor, accusing Christ and the witnesses with lies and false accusations. But notice in John 15:26 the phrase, “when the Comforter is come.“ The word “comforter“ in the Greek parakletos, and means “one called alongside to help.“ The word came to mean “the counsel for the defense.“ The Comforter refers to the Holy Spirit who is defending Christ and calling us, as individual members of the body, to witness and confirm the testimony of Christ. Sad to say, this isn’t always the case! If you’re a Christian, you’re a witness. The only question is, “Are you a good one or a bad one?“
2) As a body
The second way we can witness is as a body. The body witnesses by its unity (John 13:34,35; 17:7). Can you imagine the devastating impact that a united church would have on this world? Now I don’t mean an ecumenical church where everybody kisses doctrine good-bye, throws their arms around each other, and marches off to battle over the struggle for social rights. The body of Christ needs to be one and, sadly, we’re not! Today the testimony of the body is pathetic. Our testimony is strife, division, carnality, and confusion. And the world is rendering its verdict on the strength of these two kinds of witnesses --as individual members of the body, and the body as a whole.
In John 15:26-27, I want you to see THE NATURE OF EFFECTIVE WITNESS. Effective witness has six characteristics, and they’re all given in these two verses. Christian witness is: (1) to the world; (2) of the Son; (3) by the Father; (4) through the Holy Spirit; (5) in the individual member; (6) in the total body.
For the complete study by John MacArther
http://www.gty.org/Resources/Study+Guide+Chapter/1310


