Let`s see. From what has been shown to us until now, we can
agree that:

Red John hasn`t had anything to do with
Patrick until the moment when he felt offended by Jane in the media and
killed his wife and daughter. We know that RJ is a serial killer who
started “working” in 1998, but he
didn`t do it because of Jane, as he had nothing to do with him before
Patrick`s interview on TV.So Red John began having an obsession for Patrick because
of that incident. He was probably surprised, intrigued or annoyed by
Jane`s intelligence and capabilities of reading people, so he decided that
murdering his family is not enough. He wants to make PJ his disciple, he
wants to manipulate him, and to make him understand that even if he has a
gift (of being a mentalist) Red John is way above his powers. He wants to
make Jane accept the fact that Red John will always be one step aside, and
that his desire of revenge is hopeless. Given the fact that
killing PJ`s family was not enough for RJ, he decided to dedicate part of
his life and work messing with Jane and “testing his powers”. He has
friends everywhere, even in the CBI and his intelligence helps him always be
in the right place at the right time. More than that, Red John never lives any traces. How weird
is that? No one sees him, no one wants to speak about him. So we have a really sick and intelligent person who
has the resources, the power and the abilities to make Jane`s life a
leaving hell. He has many tools (such as Lorelai Martins) who, for some
reason (they are probably sick persons, too) are manipulated by Red John
and do terrible things to “show their respect for him”. Are they hypnotized?
No. If they were, Jane would have figured it out instantly. So how is that
possible? How can someone make another person kill, torture other people or
even kill herself for the “holly master”?

My point is this: Red John wants to
teach Jane a lesson. He isn`t anyone from Jane`s past, but someone who wants to
make PJ understand that he is nothing but a liar, a clown who does nothing but
fooling around. He took his family away, he took Kristina Frye, and he wanted
Patrick to kill Lisbon (the only person that he trusts and, probably, is in
love with). He wants to took from PJ everything he loves, so, in the end, Jane
can understand that messing with Red John is not an option.

Interesting fact: Generaly, Red John kills the persons who dare to
speak publicly about him, but in PJ`s case, he decided to  murder his family instead, and to continue
keeping an eye on Jane`s life.