According to Sidney Griedanus study book: Preaching Christ from the Old Testament.

Only 12 chapters in the New Testament don’t have a "direct" reference to the Old Testament.

12!
Do you know the implication of this? I'll explain.

1. The bible (Both NT and OT) was not written in Chapters so, even the 12 that Griedanus stated has many implied reference and quotation from the OT. The New testament is clearly the explanation (hermeneutic) of the Old.

Even without opening the NT, you should be able to preach the Gospel of Christ to anybody! You as a believer should be able to make a case for the Gospel from the OT.

2. The Epistles are not Paul's,Peter, james "Revelations" They are a body of inspired writings following a consistent flow of revelation from the Scriptures(OT)

What is the theme of these revelation? The Incarnation, sufferings, death and resurrection of Jesus! The Gospel!

The Bible follows a consistent and fail proof flow of revelation of the truth! From Genesis to Revelations! One truth stands, THE GOSPEL!

In presenting and arguing their case for the Gospel in the book of Acts, All the apostles quoted from the Old testament!

The epistles didn't magically come from air, they had a source! They are inspired writings!

This is why it will be foolish to assert that Apostle Paul taught a different doctrine, i am sorry BUT GO AND SIT DOWN! You know nothing(In love).

My thoughts are scattered but i hope to do a full thread on this some day!

Till then, please be wary of these charlatans on this streets. Make sure you're rooted in a sound local church.