M.J.,
The heavenly places or high places Paul is discussing are these seemingly important ones (false prophets and teachers in the faith) that claim superior authority for themselves. Heavenly or high places is simply another way to describe such authority. They could be doing something like teaching others that they represent the “Faithful and discreet slave,” a “Priest or some other higher level representative of God” but this is just a devilish scheme to gain power and control over your lives. The real source of such false teaching is not flesh and blood. It is spiritual wickedness and our capabilities should be such that we are able to withstand such evil and stand apart from it.
Eph 6: 11 Put on the whole armour of God, that ye may be able to stand against the wiles of the devil. 12 For we wrestle not against flesh and blood, but against principalities, against powers, against the rulers of the darkness of this world, against spiritual wickedness in high places. 13 Wherefore take unto you the whole armour of God, that ye may be able to withstand in the evil day, and having done all, to stand.
While such ones may think that they are doing great things and getting away with it Peter identifies their real position before God and the fate that awaits them on Judgment day. Paul for one had to face them personally on many occasions. Yet the circumstances or context that surrounds these two texts described here are different and they do not directly compare. You should however get the idea that all is not well in the faith and there are some really bad so called Christians authorities out there attempting to gain control over lives the teachings of which are detrimental to your salvation.
Joseph