A B757-200 Captain removed himself from flight/pay status with his airline because he believed the training provided to integrate the operation cultures of two recently merged pilot groups was inadequate to prepare flight crew to adapt to the changes.

Narrative

In my 26 years and over 10;000 flight hours at our company; this is the first time I have felt that my training was wholly inadequate. Therefore; I removed myself from further flying until I receive more training. I felt stressed and frightened during my last flight segment due to lack of proper training. At a minimum; I felt that I would be setting myself up for an FAA violation. My larger concern is about safety and not doing harm to myself; passengers; or equipment.As with most accidents or incidents; I believe it is a sequence of events that leads to dangerous; if not fatal; outcomes. The leg that I just flew was a text book example of what could happen. Luckily; I escaped without an incident. The flight was loaded with challenging issues. Some of those being a 03:00 wake up; IFR/MVFR weather; mountainous terrain; a non-precision approach; ATC delays in getting us a lower altitude (a slam dunk approach); tail winds on descent; tight turns on to the final approach course; and a short taxi in.But the most dangerous thing about all of this was the fact that my First Officer and I were reviewing and trying to accomplish the new procedures; checklists; and flows instead paying close attention to the high work load environment of our approach; landing; and taxi. We were attempting to accomplish our new procedures -- procedures that were previously rote and routine. We could not do it in a routine manner due to not having any repetitive training in a simulator or FBS (Fixed Base Simulator) to build habit patterns.Running the new procedures was a huge distraction to our normal duties and could have easily put us in a bad situation. Having to read off 3x5 cards and sticky notes to remind us of the new changes is unacceptable. Training them in a practical scenario is what needs to be done. My training concerns were presented to Flight Operations managers previous to this flight. Their response; that we are to 'fall back' to the old procedures or have 2 sets of SOPs (old and new); is beyond belief. A comment was also made that I should study and practice en route!SOP seems like just a buzz word that really is no longer expected by our company.