The Doctrine of Christ

2 John 1:9b ."... He who abides in the doctrine of Christ has both the Father and the Son."

Eternal Life is knowing God and Jesus Christ whom He has sent
John 17:3 And this is eternal life, that they may know You, the only true God, and Jesus Christ whom You have sent.

The Significance of Christ's Incarnation
John 1:14
And the Word became flesh and dwelt among us, and we beheld His glory, the glory as of the only begotten of the Father, full of grace and truth.
Romans 8:3-4 For what the law could not do in that it was weak through the flesh, God did by sending His own Son in the likeness of sinful flesh, on account of sin: He condemned sin in the flesh, that the righteous requirement of the law might be fulfilled in us who do not walk according to the flesh but according to the Spirit.
Hebrews 4:15 For we do not have a High Priest who cannot sympathize with our weaknesses, but was in all points tempted as we are, yet without sin.
1 John 4:1-3 Beloved, do not believe every spirit, but test the spirits, whether they are of God; because many false prophets have gone out into the world. By this you know the Spirit of God: Every spirit that confesses that Jesus Christ has come in the flesh is of God, and every spirit that does not confess that Jesus Christ has come in the flesh is not of God. And this is the spirit of the Antichrist, which you have heard was coming, and is now already in the world.

God's word will point you to Jesus
John 5:39 [Jesus said] You search the Scriptures, for in them you think you have eternal life; and these are they which testify of Me.
Luke 24:27 And beginning at Moses and all the Prophets, He expounded to them in all the Scriptures the things concerning Himself.
Luke 24:44 Then He said to them, “These are the words which I spoke to you while I was still with you, that all things must be fulfilled which were written in the Law of Moses and the Prophets and the Psalms concerning Me.”
1 Peter 1:10-11 Of this salvation the prophets have inquired and searched carefully, who prophesied of the grace that would come to you, searching what, or what manner of time, the Spirit of Christ who was in them was indicating when He testified beforehand the sufferings of Christ and the glories that would follow.

God's Spirit will point you to Jesus
John 15:26 But when the Helper comes, whom I shall send to you from the Father, the Spirit of truth who proceeds from the Father, He will testify of Me.
John 16:7-11 Nevertheless I tell you the truth. It is to your advantage that I go away; for if I do not go away, the Helper will not come to you; but if I depart, I will send Him to you. And when He has come, He will convict the world of sin, and of righteousness, and of judgment: of sin, because they do not believe in Me; of righteousness, because I go to My Father and you see Me no more; of judgment, because the ruler of this world is judged.
John 14:26 But the Helper, the Holy Spirit, whom the Father will send in My name, He will teach you all things, and bring to your remembrance all things that I said to you.
John 16:12-15 I still have many things to say to you, but you cannot bear them now. However, when He, the Spirit of truth, has come, He will guide you into all truth; for He will not speak on His own authority, but whatever He hears He will speak; and He will tell you things to come. He will glorify Me, for He will take of what is Mine and declare it to you. All things that the Father has are Mine. Therefore I said that He will take of Mine and declare it to you.

God's Spirit will make you like Jesus
2 Corinthians 3:15-18 But even to this day, when Moses is read, a veil lies on their heart. Nevertheless when one turns to the Lord, the veil is taken away. Now the Lord is the Spirit; and where the Spirit of the Lord is, there is liberty. But we all, with unveiled face, beholding as in a mirror the glory of the Lord, are being transformed into the same image from glory to glory, just as by the Spirit of the Lord.