Question: I read that it is possible for some Dharma cultivators to have supernormal powers. How do they come by?
Answer: Some non-Dharma cultivators have such powers too – as a result of having trained the mind in a past life, or ‘accidentally’ sharpening the mind through meditation in this life.
Question: I also read that these are meant for them to be able to better help people?
Answer: Such powers have no fixed purpose, up to the person to ab/use, and some do abuse them for personal benefit. Note that supernormal powers can be attained through various forms of non-Buddhist meditation too.
Question: After they possess such powers, are they still considered normal human beings?
Answer: As long as they are not enlightened yet, they are still human beings – with some supernormal powers. Supernormal powers attained without enough compassion and wisdom will lead to creation of much negative karma as there are now more ways to do evil. One becomes ‘demonic’! In this sense, one can lose humanity (and the precious human rebirth), if a lower rebirth results. As such, it is more important to cultivate compassion and wisdom than supernormal powers, which might naturally arise when training the mind. To look forward to such powers instead of focusing on the power of compassion and wisdom is to miss the point. Not that the Buddha forbade the open display of supernormal powers for no good reason, lest it attracts attention for wrong reasons.