Hindus, do you agree?

It is the karam which makes strong not religion, for suppose i ll give u an example a friend of mine who studied day and night got 75% and my another friend who studied hardly 15 to 30 mins got 87% whats the difference between two? second example i have one friend who applies all creams to be white and my other friend doesnt apply anything but he is white how? this is where we call this karma. We all have immense powers in our soul but there r many karms which are not letting grow due to some misuse we might have done in our past births and if we clean those karmas we would also be strong by body and mind enough.