Part 2:

Nevertheless, do not dismiss the importance of nature, attitude and education. Not all powerful people are corrupted. If a person values truth, justice, and equality above all, then no power should can or would be able to change him for the worse (this isn't wrong, but it's also not necessary).

To sum up To sum it up or, more formally, In sum, power is (consider poses) a serious test and no less a serious temptation. Thus, this it is primarily an abstract concept, used to describe a privilege given by some people to others. By itself, it does not change anything. It depends only on the person and on how he will dispose of it uses it at his (or her) disposal, and only the person is responsible for their his (or her) ("person" is singular. Many people use "they" and "their" but it is incorrect) actions.

---

Overall, these paragraphs flow well in thought and in writing. You did a good job with this!

italki didn't allow me to submit this correction as one message, I'm sorry! D: 

Part 1:

Absolute Power Corrupts Absolutely 

The proverbial saying "power corrupts" (single quotes are only used within double quotes, "Like 'this'.") conveys the opinion that, (no need for a comma here) as a person's power increases, their moral sense sense of morality diminishes (consider decreases instead). But is that really the case? Power means that With power, a person can get other people to do things for him or her. He or she gets comfortable with that. The more power he or she has, the more he or she thinks he or she can get away with stuff. People with power get arrogant. (Writing "he or she" isn't necessary, but it's more neutral. Also consider "one".)

Also, there is the problem of trying to hold on to power. The worst thing that can happen to a person in power is to lose it losing that power or the loss of that power (you can't use "it" because "in power" is not the same thing as "power"). Absolute power may conjure up dictators who have no checks and or balances. The dictator becomes more and more (consider increasingly) corrupt as he finds it easier to do the immoral things he needs to do to hold onto power.