DES MOINES — Scott Walker, the son of a Baptist preacher, learned a lot about being a politician by going to church.

He was introduced to glad-handing while greeting worshipers beside his father after Sunday services. His confidence as a public speaker began at 2, when he delivered a Christmas greeting from the pulpit, and it blossomed when he preached occasional sermons as a teenager. And now, Mr. Walker’s lifelong church involvement may be a powerful asset as he positions himself to run for the Republican presidential nomination and focuses on early primary and caucus states dominated by evangelical voters.

Already a hero to fiscal conservatives — both the Tea Party base and billionaire donors like Charles G. and David H. Koch — Mr. Walker, the governor of Wisconsin, made his most explicit appeal yet to the Christian right on Saturday before hundreds of social conservatives in Iowa. During his toughest times in office, he said, “What sustained us all along the way is we had people who said, ‘We prayed for you.’ ”

His implicit message is that in an unusually fractured Republican field, with 10 or more candidates potentially on the ballot in the Iowa caucuses next year, he is best positioned to unite the party.