Perhaps, you have studied psychology or are studying psychology as a psychology major. Perhaps, you feel like psychology does not take theology into account enough. Perhaps, you would like to take a class on spiritual psychology, the psychology of religion, or so forth. These are all good options as a seriously scholastic individual. Perhaps you would like to take a class on how to perform spiritual counseling. These may all be good options for you. Know all your options.
If your college or university offers religion classes, and if you are interested in studying religion more, then perhaps you should take one of those. You can probably use your knowledge about psychology to see how the two might relate. Perhaps there are classes or groups related to religion that are offered outside of your university that could enable you to study religion or spirituality as a psychology major without having to pay for for-credit classes.
So if you want to study religion as a psychology major, it is probably important that you know as much as you can about both subjects. That way, you can discover for yourself how they relate. Of course, also listen to others who have studied both topics, and take their opinions and perspectives into consideration too. You can perhaps find scholarly journal articles about how religion and psychology interact. So if you have access to databases with the full-text articles, then definitely take advantage of those resources.
It seems like psychology can inform humans how to feel good, to a certain extent. However, it may be that without a spiritual component, any psychology or theory of mind will be incomplete. Therefore, as a psychology major, you may want to take a class on religion or spirituality inside or outside your college or university setting. So think about finding books about the connection between psychology and spirituality, or perhaps take a class on spiritual psychology or parapsychology. Perhaps you might want to get some books on religion or spirituality and then just study those in your spare time. Whatever you decide to do, if you are psychology major, it is probably important to know as much as you can about the subject; do not limit yourself. 🙂