The power of positive thinking: If good things consistently happen, there is an excellent bet that they will continue. And the person will think they will because that will be going with the odds.
If bad things consistently happen, there is an excellent chance that they will continue. And the person will think they will because that is with the odds.
Result: The person who thinks bad things will happen (because they always have) will probably continue having bad luck. Why? Not because of negative thinking, but because whatever caused the bad luck is still there. This is also why forcing oneself to think positively almost never produces results, unless it causes the person to see clearly the root cause of the bad luck and remove it. People that have good things happen and force themselves to think negatively, likewise, will not start having bad luck unless they also sabotage the reason behind their good luck.
Prayers are not answered by God. However, one can still show someone that they care with prayer. And sometimes praying will help one find the root solution to a problem.