Jesus testified about Himself, and that was supposed to give Timothy courage for fighting the "good fight of faith." It's meant to give us courage too.
What did He say before Pilate? My impression of that incident is that He didn't say much. In English Matthew, Mark, and Luke record it as exactly five words: "It is as you say" (to the question, "Are you the king of the Jews?").
They were a sufficient number of words to get Him killed and to give us courage. Do we believe it? He's either the King or He's not.
John, we're given a little more: "My kingdom is not of this world. . . . For this cause I was born, and for this cause I have come into the world, that I should bear witness to the truth." Ah, there is a Christmas connection!
Christ's testimony before Pilate is either true, or it's not. What do you do with it?
Pilate brushed it off: "What is truth?" But it's less a matter of us deciding and more about being called by God: "Everyone who is of the truth hears [His] voice."
We take courage in Christ's testimony about Himself -- before Pilate, before the High Priest, before the people of His day. We carry the message forth from there. We "keep the commandment without spot, blameless until our Lord Jesus Christ's appearing." (1 Timothy 6:13)
Now I'm in the first chapters of Hebrews; from there we're taken back to Psalm 2, another passage about Christ the King. In it, we see rulers like Pilate put on edge by Jesus. They just hate Him! In light of God's power and fury, however, there's this recommendation -- for kings and everyone else:
Now therefore, O kings, be wise;
be warned, O rulers of the earth.
Serve the Lord with fear,
and rejoice with trembling.
Kiss the Son,
lest he be angry, and you perish in the way,
for his wrath is quickly kindled.
Blessed are all who take refuge in him.
Postscript: Can the Stable Still Astonish? -- a poem by Leslie Leyland Fields