No, You just do not know how to read the NT properly.
The verse you refer to is in Matt5.
Mt 5:17 Think not that I am come to destroy the law, or the prophets: I am not come to destroy, but to fulfil.
Mt 5:18 For verily I say unto you, Till heaven and earth pass, one jot or one tittle shall in no wise pass from the law, till all be fulfilled.
This is a prophetic statement. So now we need to see if there is anywhere in the NT that states that this prophecy has been fulfilled. After the resurrection in Luke 24...
Lu 24:44 And he said unto them, These are the words which I spake unto you, while I was yet with you, that all things must be fulfilled, which were written in the law of Moses, and in the prophets, and in the psalms, concerning me.
Lu 24:45 Then opened he their understanding, that they might understand the scriptures,
Jesus states that the words he spoke in Matt5 have been fulfilled. Now the OT law can pass away and is no longer binding on the believer.
All though you are somewhat correct concerning the Johannine comment the bible still shows evidence of the trinity.
A very small sample of relevant verses.
God the Father
Joh 6:27 Labour not for the meat which perisheth, but for that meat which endureth unto everlasting life, which the Son of man shall give unto you: for him hath God the Father sealed.
God the Son
Joh 1:1 In the beginning was the Word, and the Word was with God, and the Word was God.
God the Holy Spirit.
1co 3:16 Know ye not that ye are the temple of God, and that the Spirit of God dwelleth in you?