Baptism is read as cleansing and new birth — going under the water and rising as someone new. In a dream it marks a fresh start or entry into a new community.
When this appeared in your dream, what were you feeling?
My Cosmic Code has a private dream journal. Write a dream down and the app picks out the symbols in it, shows what dream books say about them and, over time, which words recur across your entries. The journal is stored on your device only.