Russell Vought, who is an outspoken Christian, has been nominated to become deputy director of office management and budget at the White House.
His nomination has hit the headlines, after Mr Sanders questioned his faith during the Senate Budget Committee.
Addressing an article Vought had written in which he was critical of Islam, he said: Sanders: "You think that [because] they do not know God because they rejected Jesus Christ, His Son, they stand condemned. Do you think that's respectful of other religions?"
Finishing his questioning, he said: "I would simply say, Mr Chairman, that this nominee is not really someone who this country is supposed to be about."
A number of church leaders have called on Mr Sanders to resign.
In a Facebook post, evangelist Franklin Graham said: "Is Bernie Sanders right? NO. Is he wrong? YES.
"Is Russell Vought politically correct? NO. Is he right? YES!
"Jesus said, 'I am the way, the truth, and the life. No one comes to the Father except through Me.' End of discussion."