This study investigates and evaluates the effects of an eighteen-hour weekend encounter group and three twelve-week groups--a weekly counseling group, a Bible discussion group, and a church attendance group, upon selected personality and behavioral variables, group morale and social integration. Subjects were forty-eight volunteers from a 250-member Protestant, evangelical church in a suburb of a Texas city of five-hundred thousand people. Six men and six women were randomly assigned to each of the four groups. Data analyzed were the pre-, post-, and post-post-experiment scores of the Personal Orientation Inventory, the Sixteen Personality Factor Questionnaire, and the sociometric variables based on Bonney's "Criteria for a Better Group on Sociometric Scales". The .05 level of significance was required for rejection of the null hypotheses. The statistical analyses were accomplished by applying a one-way analysis of co-variance design to the raw scores from the Personal Orientation Inventory, the Sixteen Personality Factor Questionnaire, and two of the three sociometric variables--mutual choices and opposite sex choices. The sociometric variable, choices between upper and lower quarters, was computed with the z formula. The sociometric data, mutuals and opposite sex choices on the encounter group, were further analyzed using the single-factor analysis of variance with repeated measures. It was hypothesized that the participants in the weekend encounter group would show a significantly greater change in self-actualization, positive personality and behavioral changes, social integration and group morale than would the participants in the other groups. It was further hypothesized that the weekly counseling group would show a significantly greater change in the selected variables, social integration and group morale, than would the Bible discussion or church attendance groups. It was also hypothesized that the Bible discussion group would show a significantly greater change in the selected variables, social integration and group morale than would the church attendance group. Statistical analyses failed to confirm the research hypotheses. The participants in the eighteen-hour encounter group did not show a significantly greater change in the selected personality and behavioral variables, group morale and social integration, than did the participants in the other three groups, at the conclusion of the eighteen hours or the twelve-week sessions. A partial significance was achieved by the participants in the counseling group. No significant changes were indicated by the Bible discussion or church attendance groups. The findings of this study partially support the assumption that psychological groups could enhance the ministry of the church. Therefore, it is recommended that further study on psychological-religious groups be initiated.