A church's health can be determined by what and how much of the pastor's sermon the congregation takes in. Emphasis on the "What" and "How Much", not "whether or not the congregation likes the sermon".
If that has failed, nothing else matters: Not loyalty, not commitment, not morality, not hospitality, not social charity. It is at best, a very long lasting but temporal charity organization.
One might say, better a long lasting charity organization than worshippers of cheap talks.
I shall respond: If it be the ministering from the mouth of our Lord, it ain't cheap talk.
Then some might reply: Some pastors can't preach it!
I will say: Oh but your relationship to the church must be built on the pulpit, which is the tool from which the voice of the church is generated.
"Must the pulpit be the only source of His Word in a church?"
Pulpit or not, there must be preaching and teaching of the word of God, what better place than the pulpit to convene the one and only thing (Luke 10:42) that is needed?