Ilroy said: “…you are saying that the Old Testement alone has everything we need”
No. I am saying that the entire Bible is the inerrant word of God. And there is nothing lacking. See verses for the NT:
2 Peter 3:15-16 refers to Paul’'s writings as Scripture. "…as our beloved brother PAUL ACCORDING TO THE WISDOM GIVEN TO HIM, ALSO WROTE TO YOU, speaking of these things as he does in all his letters. In them there are some things hard to understand that the ignorant and unstable distort to their own destruction, just AS THEY DO THE OTHER SCRIPTURES.
Since Peter considered Paul’‘s writings as Scripture, I should think Peter’'s writings were also considered Scripture - (You are Peter; and upon this rock I will build my church) Certainly the Gospel of Matthew, also, He was one of the twelve.
“All scripture is given by inspiration of God, and is profitable for doctrine, for reproof, for correction, for instruction in righteousness: That the man of God may be perfect, thoroughly furnished unto all good works.” Acts 3:16-17
After Jesus’ death, resurrection and ascension, the world had the Apostles whom Jesus had spoken directly to. The Apostles were writing these epistles to preserve the teachings of Jesus.
2Th 2:5 Remember ye not, that, when I was yet with you, I told you these things? (51 A.D.)
Col 4:16-17 And when this epistle is read among you, cause that it be read also in the church of the Laodiceans; and that ye likewise read the [epistle] from Laodicea. And say to Archippus, Take heed to the ministry which thou hast received in the Lord, that thou fulfil it.
Jud 1:17 But, beloved, remember ye the words which were spoken before of the apostles of our Lord Jesus Christ;
WE remember the words of Jesus throught he writings of the apostles.