My Grandma will always be steadfast in her ways. {steadfast means to believe in one thing/it depends what it is, because you can be steadfast in a few different things at once/and not change the way...
The soldiers were able to gain victory after a hard fought battle because they were steadfast in their resolve.
The columns stood steadfast and resolute.
the steadfast soldier was a story written by Hans Christian Anderson in the 1800's
He maintained his steadfast look, but gave no answer.