LYNCHBURG, Va. — Mitt Romney traveled to Liberty University, the spiritual heart of the conservative movement, on Saturday, seeking to quell concerns about him among evangelical voters by offering a forceful defense of faith and Christian values in public life.

At a graduation speech at the college, founded by the evangelical leader Jerry Falwell, Mr. Romney made the case that he is bound theologically and politically to the same belief and value system as Christian conservatives, though he never explicitly mentioned his Mormon faith.