There have been a good number of research studies linking religious beliefs and practices to wellbeing. These studies, in a way, allude to human beings longing to have a transcendental experience as part of their nature given that religion is not epiphenomena. This explains why religious beliefs and practices are a global phenomenon.This study examined religious activities and the psycho-spiritual wellbeing of senior secondary school students of Marist Comprehensive Academy in a causal-comparative study with Uturu Secondary School in Abia State of Nigeria. The study was guided by the Social Functionality Theory of Religion with the following research objectives: to assess the prevalence of religious activities going on, to examine the level of psycho-spiritual wellbeing of the students in both schools, to investigate the influence of religious activities on the psycho-spiritual wellbeing of the students, and to identify other ways of enhancing the students’psycho-spiritual wellbeing. The study adopted a causal-comparative (retrospective type) design approach with a structured survey questionnaires for data collection.The target population is676 senior secondary school students comprising 384 girls and 292 boys, with a sample size of 251.Version 25.0 of the Statistical Package for Social Sciences (SPSS) was used for the computation and analysis of the data collected through Google Forms. Descriptive statistical measures (namely mean, standard deviation, percentages, tables, frequencies and bar charts) and inferential statistics (for hypothesis testing) like mean comparison, independent “t” test and Pearson’s chi-squarewere used in the analysis of the data collected. The findings retained the hypothesis in that there is no significant difference in the level of psycho-spiritual wellbeing of the students of Marist Comprehensive Academy and Uturu Secondary School with respect to religious activities.Other findings were that the psycho-spiritual wellbeing of the students of both schools is highand that both variables are independent of each other.More emphasis should be given to the intervening variables.