What does one believe in to be saved?
Salvation, to start with. That you don't have it, that you need it, that you can get it.
Then secondly, a method of salvation, a process. These differ from church to church, but can loosely be split into two groups, and qualified as real or imaginary.
If you believe that salvation is something that only involves the world inside you (i e is
imaginary) then it follows that you can get it simply by believing things. These tend to consist of tenets, often organized into a creed and/or expressed as a prayer.
On the other hand, if you believe that salvation in some sense involves the world outside you (i e is
real) then it follows that in order to get it you are going to have to actually do something!
So, which is it? Is your faith real? (alive)
In which case, it's going to necessarily include works.
Or, is your faith imaginary? (DEAD)