Why does the Christian doctrine seem so far from the Bible?

Upon reading the Bible, I have found that that Christian doctrine differs heavily from the scriptures. A few of the differences: 1. Circumcision 2. Feast days 3. Following the statutes & judgements 4. Keeping the Sabbath How is it that Christianity, which is supposed to be followers of Christ, don't seem to follow him at all? I hold the view that there is only one Christ who brought one doctrine and therefore Christianity should all be following the same teachings. Yet there are many divisions and many varying teachings.