BEARING WITNESS
In court, bearing witness is telling the truth about what you've seen and heard. John the Baptizer was doing the same about Jesus. If we witness, we can tell others about something the Lord has done in our lives, whether relating to Salvation or some other matter of His provision. We can witness to others about His healing, His sustenance (He gets us through things), His grace, etc. The purpose of bearing witness about Jesus is so that others may find Him and believe to eternal life. 'Wit-ness' literally refers to having a knowledge about something, and we need to share what we know about Jesus!
Application: Do we bear witness of the Light? Note that the purpose of both the testimony of the Apostle John and John the Baptizer was to bring people to believe in Jesus. Are we doing this?
Witnessing is literally telling others what the Lord has done and who He has been in your life. What has He done in your life? How can you tell others?