19 . . .even so doth every man that is cursed bring upon himself his own condemnation.
God is not vengeful. Some tragedy comes to the innocent as well as to the guilty. But God does not manipulate us by immediately punishing sin and rewarding righteousness.
Having said that, it's evident to even the casual observer that much misery comes into our lives by invitation. A man pursues a quick release from stress through a few beers, becomes dependent, and over time loses his job, wife, children, and self-respect.
A woman looks for comfort in talking about her personal life with a friend at work or school. The friendship looks more and more attractive and is an escape from the hard work of marriage. She slips into adultery and betrays the sacred covenants she made with her husband and the Lord and loses her marriage, her family, and her church membership.
There is enough challenge in life without inviting condemnation on ourselves through choice. Mormon shares this observation at the end of chapter 3:
27 For every man receiveth wages of him whom he listeth to obey, and this according to the words of the spirit of prophecy; therefore let it be according to the truth.