New York: A person's faith in God increases when he or she thinks of "what might have been" if an important event would have turned out bad, a study says, showing how believers confirm their religious conviction via deliberate and rational cognitive processes.

"I became intrigued by the question of how people perceive God as an active, trustworthy and giving influence in their everyday lives," said lead study author Anneke Buffone from the University of Pennsylvania in the US.

"Why is it that the vast majority of Americans and many people across the globe, perceive a divine or spiritual influence in their lives, even in modern world where many mysteries of the past have been scientifically explained," Buffone added in the paper published in the journal of Social Psychological and Personality Science.

To examine these perceptions, the team focused on counter-factual thinking.

The researchers specifically explored downward counter-factual thinking, thoughts about how life would be worse if an important life event had not occurred.

In their first study, 280 undergraduate students wrote an essay describing an important positive or negative life event from their past.

Following this exercise, the participants answered a series of questions related to their strength of religious beliefs including faith, behaviour and how much they felt the influence of God.

The results suggest that counter-factual thinking leads believers to the belief that the event did not occur by chance alone and leads them to search for a source, in this case God, and this in turn leads to an increase in religious faith.

The authors found effects to be strongest when people thought about the events in a downward counter-factual direction, that is, when they thought how life would be worse if an event had not occurred.

The team conducted another study with 99 non-college participants and went through a similar essay and questionnaire process like previous study.

The results from this second replicated with the first study.

"From a scientific standpoint this work helps explain how religious conviction can prevail despite a lack of concrete, physical evidence for religious claims."