One way that the birthright experience affected me spiritually is in how it changed my perception of Judiasm from a separate entity to a lifestyle. Prior to my Israel trip, I had viewed Judaism as something that you isolate to synagogues, private moments, and the occasional ritual. During my trip, while waiting in line for food in Jerusalem, I witnessed a crowd of people celebrating a Bar Mitzvah. Unlike in the United States, where Bar Mitzvah celebrations are black-tie events with invitations and ceremony and confinement to a building, this was in the street, in such a way as to invite anyone into the celebration and let them join into the happiness of the moment. This concept, that (In Israel, at least) Judaism can be a normal part of life instead of a distinct and separate thing was very powerful and has affected the way that I think about similar ceremonies at home.
Another spiritual thing that happened to me this year was while sitting in Rosh Hashana services, I realized that one of the largest things holding me back during the prior year was my difficulty in being willing to forgive myself for past errors or sadness. Being able to take time during Yom Kippur to resolve why that was the case, and what I would do, internally, to change my outlook. It was a spiritual moment because it allowed me to connect with the intended focus of the holiday, atonement, and get some sense of relief from having a plan for self-improvement.