What role does religion play in success and happiness?

Univesity of Miami Professor Michael McCollough has authored a study that unpacks why religious people are more successful, and generally more sanguine with their lives than secular folks. It seems that they have more self control:

Research has also shown that young children who do well at delaying gratification (i.e., forgoing a small reward in the present so that they might obtain a larger reward after time has passed) perform better years later on measures of academic achievement and social adjustment (Mischel, Shoda, & Rodriguez, 1989). Some social scientists consider delay of gratification to be an important dynamic underlying the behavioral choices of people who believe in an afterlife in which their behavior during this life will be judged. For people with strong beliefs in such an afterlife, it would indeed be rational to deny short-term gains that might come from engaging in behavior that is proscribed by one's religion because the long-term (eternal) gains of not engaging in the behavior might outweigh the short-term gains associated with engaging in the behavior (Azzi & Ehrenberg, 1975; Iannaccone, 1998).

In other words, certain perspectives make it easier to ignore ones salivary glands when confronted with a pot of gold--and it seems it will also make one more successful as well as make one less prone to depression.

The Sages of the Talmud had much to say about self destructive behavior and its origins. Review some of the earliest understanding on the story of Cain and Abel--the first murder.
Here are some seemingly conflicting tidbits:

“Both small and great are there and a servant is free from his masters.” (Job 3:19) As long as a human lives, he is a servant to two urges. A servant to his Creator and a servant to his desires. When he serves his Creator he enrages his desires and when he serves his desires, he enrages his Creator. When he dies, he is liberated. The servant is free from his masters. (Midrash Ruth 3:1)

Rabbi Nachman Bar Shmuel Bar Nachman in the name of Shmuel Bar Nachman said: “And it was very good.” (Genesis 1:31) ‘And it was good’—refers to one’s good inclination, ‘and it was very good’—refers to one’s evil inclination. You mean that an evil inclination is very good?!!!?!??! If it were not for the evil inclination one would not build a house, marry and have children, nor engage in commerce. Thus Solomon wrote in Kohelet “skillful enterprise come from men’s envy of one another.” (Geneis Rabba 9:7)

It's another one of Ravavi's faux Talmud pages for your perusal and benefit.