Be good... Live good

When Boja Maharaj (King) asked the great poet Kalidasa as what is the essense of 1 crore books written about life, he answered...

"Paropakaraha punyaya, papaya parapeedanam".
To do good to others is merit. To hurt and cause suffering to others is sin (In this context, trouble refers both bodily and on the mind level).

Speaking of how your thoughts can affect your behavior, here is a good explanation. Your thoughts reflect your words... Your words reflect your deeds... Your deeds become your habits in course of time... and your habits shape your personality. Ofcourse, your personality can decide your future.

Just as how we all believe that energy can neither be created nor be destroyed, and can only be transformed; all the good you do will not go in vain. The more good you do to others, more good will happen to you.