Isaiah's Explanation

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 (Father is in me - John 10:38), and the Holy Spirit (Spirit of the Lord is upon me - Luke 4:18).


Isaiah's Explanation

When Christ was on the Cross, The God of Trinity (Father, Son and Holy Spirit) all three of them suffered for our Salvation, that's why Prophet Isaiah wrote like this - 6.On this mountain the Lord of hosts will make for all peoples a feast of rich food, a feast of well-aged wine, of rich food full of marrow, of aged wine well refined. 7.And he will swallow up on this mountain the covering that is cast over all peoples, the veil that is spread over all nations. 8.He will swallow up death forever; and the Lord God will wipe away tears from all faces, and the reproach of his people he will take away from all the earth, for the Lord has spoken. 9.It will be said on that day, Behold, this is our God; we have waited for him, that he might save us. This is the Lord; we have waited for him; let us be glad and rejoice in his salvation - Isaiah 25:6-9

And that was the reason, the Trinity God appeared to Abraham by the Oaks of Mamre, and Abraham also asked all three of them to stay under the tree while making the Bread, In the prophetical incident, the tree(oaks of Mamre) is representing the cross where our Savior died for our sin and salvation - 1.And the Lord appeared to him by the oaks of Mamre, as he sat at the door of his tent in the heat of the day. 2.He lifted up his eyes and looked, and behold, three men were standing in front of him. When he saw them, he ran from the tent door to meet them and bowed himself to the earth 3.and said, O Lord, if I have found favor in your sight, do not pass by your servant. 4.Let a little water be brought, and wash your feet, and rest yourselves under the tree, 5.while I bring a morsel of bread, that you may refresh yourselves, and after that you may pass on—since you have come to your servant. So they said, Do as you have said - Genesis 18:1-5

And for the same reason, Jacob took branches from three types of trees(Poplar, Almond, Plane), here the three types of trees are representing our Heavenly Father(Father, Word, and the Holy Spirit), and the Branches from these three trees are representing the Son Jesus Christ, and Jacob wounded all tree types of branches by peeling them, this is to tell the truth that the Father, Word, and the Holy Spirit all three of them who is in the Son Jesus Christ suffered for our sin and salvation - 37.And Jacob takes to himself a rod of fresh poplar and almond and plane-tree, and peels in them white peelings, making bare the white that [is] on the rods, 38.and sets up the rods which he has peeled in the gutters in the watering troughs (where the flock comes to drink), in front of the flock, that they may conceive in their coming to drink. 39.and the flocks conceive at the rods, and the flock bears striped, speckled, and spotted ones - Genesis 30:37-3911