Listen further: "that Jesus is the Son of God." That is for all of us, Jew and foreigner, insider and outsider. This Jesus is in a distinctive sense the Son of God, the only begotten Son. This pure loving pleading wooing suffering dying rising-again Jesus, this is the only begotten Son of the Father. All there is in a Father comes to, and is in, an only begotten son. This is God Himself coming to us in His Son.
Once let this sift into thought and heart, then who would not believe, and trust, and love, and fall on his face in the utter devotion of a voluntary slave before such a God!
And so believing, trusting, loving, touching, His life flows in and fills up and floods out. We have it now. That word eternal, used so often by John with the word life, is not a mere length word. It is not a calendar word. It tells the sort of life, the quality of life, that comes in through the opening door of our believing. This is John's back-door key, but it lets you clear in through the whole house.
Then there is the side-door key. It hangs at the side, a bit towards the back. It is in the Thursday night talk, as we commonly call it, that last heart-talk with the inner group on the betrayal night. It is in chapter sixteen, verse twenty-eight: "I came out from the Father, and am come into the world: again, I leave the world, and go unto the Father."
Run through this Gospel with that fresh in your mind, and it is perfectly fascinating to find how much like a magnet it is, picking out to itself so many bits from the Master's lips that fit exactly into it. Jesus' constant thought was that He used to be with the Father; He came down on an errand to the earth. By and by when the errand was done He would go back home again.
This sentence becomes a simple, exact, comprehensive outline of the entire Gospel. Notice: "I came out from the Father": that is chapter one, verses one to eighteen. There Jesus is seen coming down from His Father's own presence. Then chapter one, verse nineteen through to the close of the twelfth chapter is fully described and covered by the next clause, "and am come into the world." Here He is seen in the world, in the midst of its crowds and contentions and oppositions.
"Again, I leave the world,"—chapters thirteen to nineteen. In chapters thirteen to seventeen He is tenderly leaving the inner circle. In chapters eighteen and nineteen He is going out of the world by the terrible doorway of the cross it had carpentered for Him. How quietly He says the words, though the terrible going is yet to come, and is now so near that He can already feel the shame and the thorns and the nails.
And as quietly He looks beyond and adds, "and go unto the Father." In chapters twenty and twenty-one He lingers a little for the sake of these being left behind, but His face is already turned homeward. They would hold Him in their midst. He quietly tells them that He is going back home to the Father to get things ready for them, as He had said.
He Comes to His Own.
The front-door key hangs right at the very front, outside, low down, where even a child's hand can reach it. It is in chapter one, verses eleven and twelve: "He came unto His own, and they that were His own received Him not. But as many as received Him to them gave He the right to become children of God, even to them who believe on His name." This is the great key, the chief key to this whole house. It flings the front door wide open and you are inside at once, and take in the whole of the house at a glance, one glance, one wonderful glance.