After a decade starring for the St. Louis Cardinals, Albert Pujols is already compared with names in the highest reaches of baseball's pantheon: Ruth, Gehrig, Aaron, Mays. Slugging his way toward the Hall of Fame, Pujols has raised the game's standard for greatness beyond any statistical measure. But the standard by which Pujols measures himself has less to do with baseball performance than with honoring God and exemplifying his faith for the millions who follow him.

From his birthplace in the Dominican Republic to his high-school days in Kansas City, from a single season in...