The early Jewish Christians remained Jews, with no thought of embracing a new religion; they were merely convinced that Jesus was the “Messiah” or the “Christ,” and they regarded his Messiahship as much more important than any new moral message he might be bringing. That is, they believed in Jesus, rather than that what Jesus taught was true — an attitude that remained characteristic of most Christian thought until the nineteenth century. This conviction involved certain intellectual beliefs or expectations: notably, that only righteous, Law-observing Jews who accepted Jesus as the Messiah would share in the Kingdom he would set up on his second coming. But their faith in Jesus was primarily a commitment to Jesus: it was practical rather than intellectual.
Much the same holds true of Paul, though his conception of the nature of the work of Christ was quite different. For him, this was not to found the Kingdom, but to transform human nature from flesh to spirit, and thus to save individual souls from bondage to sin and death. By accepting and believing in the Christ, men are united to him in a mystical union, die with him to the old Adam, put off the flesh with him, and rise with him, completely transformed in their nature, to live a new and divine life, a life “in Christ.” This is all for Paul an intensely personal and practical religious experience. Believing in Christ is no mere intellectual assent, and acceptance; it is utter absorption.
Hence neither the early Jewish Christians nor Paul made central what Jesus taught.
Randall, John Herman. 1970. Hellenistic Ways of Deliverance and the Making of the Christian Synthesis. New York: Columbia University Press. pp 146f