I think this is a dreadful and perverse doctrine which basically nullifies the teachings of Jesus Christ. I hope and pray that you do not actually believe such things.
If Jesus were here now, I suspect He would say, “Why do you nullify My teachings for the dispensationalist tradition of men?” Dispensationalists have essentially taken the Crown from Our Lord’s Sacred Head and put it on His Apostle Paul, declaring Paul to be our Messiah and Supreme Legislator.
Christ’s death does not abolish His teachings, but the Old Law. While Christ lives He preaches His Gospel which is the New Law. The New Law comes into force at His death when He merits grace and salvation for all.
All the teachings of Jesus Christ are part of the New Law and the New Testament. All of His holy teachings and doctrines are still in effect. Don’t let any dispensationalist tell you otherwise.