So why isn't all this clearer?
Making it clearer does not eliminate the problem. Just in case you were wondering I am in no way trying to sell Christianity to you, but you're kind of putting me on the defensive by making me the spokesperson.
The Bible has over 60 books and lacks any sort of clarity that allows believers a coherent understanding of what it demands or requires. The Jesus teachings are basic liberal human attitudes but we see many Christian sects that largely ignore what jesus taught for an incoherent dogma that, to my mind, is anti-Christ. So an atheist can understand this, but some Christians can't?
The first part is a collection of Jewish works 66 of them, not counting the ones protestant Christians don't print. In the Jewish concept called tzim tzum it is thought that pouring knowledge into an unprepared person is harmful, like breaking a wineskin with too much wine or like when Achelus flies too close to the sun and falls. You could destroy the student by such sloppy teaching! The Jewish (rabbinical) process is intended to be thorough, completely replicating knowledge in the student and not only knowledge. Exact replication is the absolute goal, and to this end things are not plainly explained. You have to work for it, and the Jewish scriptures were only grudgingly put onto paper when there was no other way to keep them; because one Jewish value is to not harm people -- not even with knowledge. The knowledge is important and sacred, for it has the power to free the mind.
In addition the scriptures are not written as a textbook, are not written to a post enlightenment crowd of individualist thinkers, are not written to non Jewish people with no Jewish parents who have never been to Jewish weddings or festivals or anything. The Jewish scriptures may open in the hand, but they are still closed to the eyes. This is for your protection and benefit. Its not intended as a slight or to harm you, just as when the Buddha speaks in riddles its not a slight. It is to draw you, the student, into a more perfect understanding than could be obtained through mere volume intake of knowledge.
Christianity departs from that. Jesus departs from that, however the Jewish scriptures are really supposed to be reserved to serious students. They are not these days, and that does cause a lot of confusion yes.
Now those same scriptures are very clear, but they are not clear to casual readers and purposely so. You should not read them and think they are laid out as a textbook to instruct you about the Jewish people. They were never written to you, for you or even with you in mind.