Possible Clues:

• Abandonment of one's beliefs
• Desertion from a job, say? Possibly
• Renunciation of a faith
• First letter is delivered to say bully provided religious abandonment
• Teetotaller hides all the letters for Bob Sykes Centre to change religious outlook
• Rejection of a job when variable
• A job so variable leads to abandonment of principles
• Mixing soy with pasta is heresy!
• Cooking pasta with soy is treachery
• Renunciation of belief