The Father's Witness
The English word "witness" can simply mean "someone who sees an event and tells what happened." But it also means "testimony by word or deed," which is actually closer to the original Greek word that was written in the Holy Scriptures. Pronounced mar-too-reh-oh, it means to bear witness, not merely as a matter of words alone, but by living a life as a testimony of the words. Interestingly, and unfortunately, the English word "martyr" originated from that same Greek word, mar-too-reh-oh, which although meant someone who lived a life of witness, came to mean the death of those who did so, at the hand of those who did not.
"For the works which the Father hath given me to finish, the same works that I do, bear witness of me, that the Father hath sent me"
Jesus Christ, the Son of God, was an obvious witness of God The Father. What greater witness of the existence of a Father can there be than the presence of his offspring? But The Father was also a witness of His Son, giving cogency to His Son's existence and mission. They are a witness of each other. In the same way, the prophet John (known as "John the Baptist") was a witness of Christ's coming (see John's Testimony) in the same way that Christ is the witness to The Father's coming (see The Throne Of God, From Heaven To Earth).
"5:31 If I bear witness of myself, my witness is not true. 5:32 There is another that beareth witness of me; and I know that the witness which he witnesseth of me is true.
Fact Finder: Why was Christ sent ahead of The Father? What was Christ given to do?