The fundamental doctrinal tenets of Christianity can be traced back to Paul -- not to Jesus. In contrast, the original Christianity before Paul is somewhat difficult to find in the New Testament.
Perhaps because of the long informal establishment of (Protestant) Christianity as America's culture-religion, long ago the American Church became confused about what exactly it means to be the Church.
Here is the crux: Moral nature is lost in the way the Church has evolved. It is the past we are to worship, not anything living.