Please help me understand grammar rules better. I have few sentences below and i also have my explanation in parenthesis for it. Please correct me, thanks.
There is no one best way to do a job right, or to make a sale. There are as many best ways as there are creative minds.
(In the above sentence or is coordinating conjunction so i have used comma before or, but i am not sure if comma is needed in the second part). The sentence is good enough. You don't need the comma here.
When people resent an idea, that means they are using traditional thinking. Their mind is paralyzed. OK
If you believe something is impossible then it is, really. But
,if you believe it is possible then solutions will come up.
(Do i need a comma after but. No
Also, is the first part of the sentence correct).
It's grammatically correct. (Obviously it's not factually correct, but it's acceptable as a motivator for those inclined to believe this sort of thing.)
Personally, I'd use a dash before 'really'.
If you think you can do more, then your brain shows you the way.