Apostle John who was with Christ until his last moment of the crucifixion, has revealed that Jesus Christ is not the image of Word alone, but the Image of Father, Word and the Holy Spirit, and we must believe in him to overcome this world - 5.Who is it that overcomes the world? Only the one who believes that Jesus is the Son of God. 6.This is the one who came by water and blood—Jesus Christ. He did not come by water only, but by water and blood. And it is the Spirit who testifies, because the Spirit is the truth - 1 John 5:5-6
To understand this in a better way, apostle John first explaining the Trinity of our Heavenly Father as Father, Word and Holy Spirit - because there are three who are testifying in Heaven: the Father, the Word, and the Holy Spirit, and these three are one - 1 John 5:7
And then he explained about the Son Jesus Christ, that Jesus had all three of them(Father, Son, and the Holy Spirit) in him - and there are three who are testifying in the earth: the Spirit(Holy Spirit), and the water(Word), and the blood(Father) and the three are into the one(Jesus Christ) - 1 John 5:8
That was the reason Apostle Paul is saying that Jesus Christ is the Image of the invisible God - The Son is the image of the invisible God, the firstborn over all creation - Colossians 1:15 that means in Jesus Christ we can see the Son (The Word became flesh - John 1:14), and our Heavenly Father (Whoever has seen me has seen the Father - John 14:9), and the Holy Spirit (The Spirit of the Lord is upon me - Luke 4:18).
David's Explanation
It's a tough day for king David as he is fleeing before his son Absalom - So David said to all his servants who were with him at Jerusalem, Arise, and let us flee, or we shall not escape from Absalom. Make haste to depart, lest he overtake us suddenly and bring disaster upon us, and strike the city with the edge of the sword - 2 Samuel 15:14
This is one of the darkest moment in King David's life, and this made people of Jerusalem also weep for him - And all the country wept with a loud voice, and all the people crossed over. The king himself also crossed over the Brook Kidron, and all the people crossed over toward the way of the wilderness - 2 Samuel 15:23
But Its prophetical (foretelling) moment for King David to tell the world that Christ has to go trough such a painful night in the same Mount of Olives - So David went up by the Ascent of the Mount of Olives, and wept as he went up; and he had his head covered and went barefoot. And all the people who were with him covered their heads and went up, weeping as they went up - 2 Samuel 15:30