This study compared behavioral (fulfillment of religious commandments), and motivational components of religiosity among 54 Jewish adolescents (aged 13-21 years) and 35 adults (30-60 years) with intellectually disability (ID) (IQ = 40-69). A special questionnaire was constructed. Results yielded similarities between the religious profile of individuals with ID and those of the general population. A different pattern was found between the age groups. Adolescents fulfilled Jewish commandments to a greater extent than the adults. Social psychology theories regarding religious change/stability over the lifecycle can serve as an explanation for these findings. Adults exhibited a more mature motivational component of fulfilling commandments (dependence on God) than the adolescents (Divine decree--obedience to God and receiving external rewards). Regression analysis indicated that among adolescents, the cognitive level contributed to the explained variance of the behavioral components, whereas among adults, chronological age contributed to the explained variance of the behavioral components. (Contains 1 figure and 2 tables.)