Though one might find it comforting that a leader shares one’s personal religious faith, I myself would be far more comforted by having a competent individual in the job who does his or her work with care and responsibility, no matter where he or she spends the Sabbath.
It mattered very little that President Bush professed to be a Christian while Americans drowned and died in New Orleans. It mattered very little that his advisers and appointees claimed kinship with Christ while waging underplanned, unprovoked, illegal war with Iraq and dividing the spoils amongst campaign contributors and old friends.
Being president, leading this country, is a job, with particular tasks that need to be done to certain standards outlined in writing.
As in any job, it is your fulfillment of those requirements that matters. If you cannot perform to those standards, your prayers may make you feel better, but they won’t satisfy your bosses.