All the pains and pleasures man experiences are the results of his own actions and not due to any act of the Divine. God is only a witness. God is like a postman. He delivers to you whatever letter is addressed to you. The grief or joy you derive from the contents of the letter are your own. Likewise, the suffering or happiness one experiences are the results of one's own bad or good deeds, and are not derived from God. However, there is the operation of special grace on certain occasions. When you pray to God with a pure heart, without a trace of selfishness and with sacred feelings, God confers special favor. Moreover, when a person has done some unique act of sacrifice in a previous life or at any time in the past, the Divine confers an appropriate reward for it at the proper time.
(Sanathana Sarathi, Aug 1996, pg 218)