“The Dean” has not seen this question before, and it’s an interesting one. Obviously, the officials at the private Christian universities on your list believe that students who actively practice their faith are best suited to their school. By requesting a letter from a pastor, they can gauge which applicants seem most involved at church, and they may be wary of those candidates who can’t find a pastor to write on their behalf.
But, on the other hand, I think that such schools might be willing to also welcome an applicant who is seeking a stronger religious connection. So here’s what I suggest you do: