As the author points out, there are 121 denominations and then some of Christianity. He points out that there are disagreements over the "fundamentals" of faith and gives as an example the fact that a large number of ministers don't believe in the "resurrection."
Some Christians believe the resurrection was a physical event, and some believe that it was a spiritual event. So, can we come to some agreement about this by sitting down and talking about it? Maybe.
Furthermore, and this is more to the point, some Christians believe that in the Last Days there will be a physical resurrection of the dead, while others believe there will be a spiritual resurrection of the dead.
So, to answer your question, no, I don't think it's too much to ask that Christian pastors believe in Christianity. But there are at least 121 different definitions of what that means.
Should Christians set aside their differences and unite? Of course they should. Will they? I doubt it.
I doubt that even one of those denominations, no matter how liberal, officially teaches that the physical Resurrection of Christ is an open question.
A denomination which teaches such a doctrine, like the Unitarians for example, is a non-Christian religion.
"Some Christians believe the resurrection was a physical event, and some believe that it was a spiritual event. So, can we come to some agreement about this by sitting down and talking about it? Maybe."
I thought all Christians believed Christ literally rose from the dead physically as well as spiritually.
Thre's that story about the apostle Thomas actually putting his hands in Christ's wounds. If he only rose spiritually, that would not be possible.
The only Christians I know of who might not believe in the physical resurrection are Gnostics and I don't think there are too many of those around.
Either Jesus Christ, the Son of God, rose physically from the dead, or he didn't.
It's really that simple. Choose which side you're on and be done with it.