Here are examples of the word/phrase "fearlessness" used in a sentence and paraphrased in a sentence...
The fearlessness he showed motivated me to conquer my own fears.
The valiantness he showed motivated me to conquer my own fears.
His fearlessness is what kept him going through tough times.
His bravery is what kept him going through tough times.
My fearlessness is what got me this far.
My intrepidness is what got me this far.
Other Examples...