Witness

John 1:6-9 (NIV)
⁶ There came a man who was sent from God; his name was John.
⁷ He came as a witness to testify concerning that light, so that through him all men might believe.
⁸ He himself was not the light; he came only as a witness to the light.
⁹ The true light that gives light to every man was coming into the world.

John had a unique place in the revelation of Christ.  It was given to him to announce the coming of the Lord and to identify Jesus as the Lamb of God.  He came as a witness to the light which shines on everyone in the world.  His witness was the signal that the unfolding of the kingdom of God was at hand.  

The Lord told John to look for a sign.  The sign was given.  John witnessed the Holy Spirit descend on Jesus.  He testified to that fact.  He announced the coming light.  

Like John, you and I are now witnesses of that same light.  Unlike John, we witness from within the kingdom of God.  That same Holy Spirit that descended upon Jesus has now come to us who believe.  The light spreads and grows as we reflect that holy light, as we witness to the grace and truth in Jesus.  Like Christ, that witness is in word and deed.  The purpose is the same: that all men might believe.