Most characters should be polytheistic and invoke various gods depending on what they're doing or where they're going, and not have one particular deity.
Having a singular deity is the unusual exception.
In d&d, it's traditionally accepted that everyone knows all the gods exist, but most people choose a favorite to worship. That doesn't exclude them from making prayers/etc to the other gods, but most characters have a "primary" good that is their bff diety.
