Everyone here who devotes themselves into meditation practice will get benefits from it and eventually grow powers in accordance to the practice, sooner or later. Some people are born with talent, and like athletics, gifts will come faster, others will have to persists and if they are persistent they will become better than the lazy talented.
All human beings have the ability to develop spiritual power, same as virtually the majority of people can develop athletic skill or any other skill if the practice is done.
Some people are talented and sleep on it, some others want to grow and are resilient, therefore they grow regardless of natural talent. All humans have been given by Satan the ability to spiritually advance. So it's up to people to consider this. Also, spirituality is not some 'addon' to life, it's quite essential. Not advancing spiritually has a backlash imposed on by nature.
Depression and many other things, such as issues stemming from lack of self-understanding can become gigantic if people don't advance spiritually. Not advancing is the same as abstaining from food.
However, undeniably, the philosophy and mindset of the JoS is a no-bullshit approach to life and spirituality, that emphasizes on personal thinking and freedom. Therefore even if someone wants to remain on this level, which is NOT advisable for many reasons, there are still benefits for anyone who wants to be with Satan rather than disturbing and destructive modes of thinking that ruin people mentally.
The above doesn't reduce the necessity of spiritual advancement.
most of the time 
