It has been almost three years since the Supreme Court last heard arguments in a case that turned on one of the religion clauses of the First Amendment, a curious lull in what had been a signature project for the court led by Chief Justice John G. Roberts Jr.: to bolster the place of faith in public life.

The hiatus is over. In the space of a month this spring, the court will hear three important religion cases. The first one, to be argued Monday, asks whether a Catholic charity in Wisconsin…