This study examined the degree to which certain religious/spiritual constructs simply reflect personality variables and to what extent they describe unique components of individual differences. It assessed the incremental validity of several recent or widely used religious measures over personality dimensions in predicting quality of life, racism, and sexual attitudes in a national sample of religiously committed adult Christians (n = 386). Religious measures were chosen to reflect a variety of constructs and included the Faith Maturity Scale, Greeley Grace Scale (a measure of images of God), Religious Problem-Solving Scale, Spiritual Experience Index--Revised (a measure of spiritual maturity), and the Ways of Religious Coping Scale. Personality was measured by the NEO Five-Factor Inventory in order to provide an adequate and universal framework. Criterion variables representing constructs important to both psychology and religion included the Life Satisfaction Domains and the Life-3, Modern Racism, and the Valois Sexual Attitude scales. Step-wise regression analysis indicated that most religious measures contributed significant variance above personality to the prediction of racism (from 0.8% to 7.6%) and sexual attitudes (from 1.7% to 19.6%), but the contribution to quality of life was notably uneven (from 0.6% to 1.7%). The Faith Maturity Scale and the Spiritual Experience Index showed the most consistent indications of incremental validity across the chosen outcomes, while the Greeley Grace Scale showed the least. Results suggest that religious and spiritual constructs should be carefully selected because some popular constructs may offer little additional predictive ability apart from personality. Results also suggest that selected religious constructs are important predictors distinct from the current five-factor personality model and may represent unique and potentially interesting descriptors of individual differences useful for both mainstream research and clinical practice. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]