Sounds like YOU are adding to the gospel, or maybe just confused.The only condition is grace through faith
A licentious person has belief, but has no faith it is dead which is why they have no works.
A legalist may have belief but they have no faith its why they add works to the gospel.
To have belief means to have faith. Faith, as a noun, is WHAT is being believed.
They go together. Can't be separated.