Research largely shows that religion and spirituality have a positive correlation to psychological well-being. However, there has been a great deal of confusion and debate over their operational definitions. This study attempted to delineate the two constructs and categorise participants into different groups based on measured levels of religious involvement and spirituality. The groups were then scored against specific measures of well-being. A total of 205 participants from a wide range of religious affiliations and faith groups were recruited from various religious institutions and spiritual meetings. They were assigned to one of four groups with the following characteristics: (1) a high level of religious involvement and spirituality, (2) a low level of religious involvement with a high level of spirituality, (3) a high level of religious involvement with a low level of spirituality, and (4) a low level of religious involvement and spirituality. Multiple comparisons were made between the groups on three measures of psychological well-being: levels of self-actualisation, meaning in life, and personal growth initiative. As predicted, it was discovered that, aside from a few exceptions, groups (1) and (2) obtained higher scores on all three measures. As such, these results confirm the importance of spirituality on psychological well-being, regardless of whether it is experienced through religious participation.
And before anyone says this is a C & P, here is the link.
http://link.springer.com/article/10.1007%2Fs10943-011-9540-2