Petrus stated:  "People were created by God to live according to His design for their own wellbeing and for the common good. These "rules" were indeed made for man and it's one of the jobs of the Church to teach [them]."

To which you responded:  ""Which is the diametrical opposite of what the Jesus of the New Testament actually taught."

What part of Petrus' statement could you possibly argue with?  That people were created by God to live according to his plan?  That God had a plan for mankind?  That his plan was designed for our own well-being?  That God's plan, if followed, furthers the common good?  

Where did Jesus teach "the diametrical opposite" of what Petrus says?