I think we make two mistakes in our attitude toward our Christian leaders, one in not being sufficiently grateful to them and the other in following them too slavishly.
The first is a sin of omission, and because it is something that is not there it is not so likely to be noticed as a sin that is plainly present. For instance, it is a sin to be ungrateful to a man who has befriended us, but it is not as bad or as obvious a sin as stealing his pocketbook.
To be grateful to God's servants is to be grateful to God. The benefits we receive from them result from God's working through them, but as free agents they could have refused to cooperate. That they cheerfully yielded their members to the Spirit for our good puts us under continual obligation to them. Because they are so many, and because the vast majority of them have long fallen asleep we cannot make a like return to them in person; the only way we can discharge our obligation is to be thankful. Gratitude is an offering precious in the sight of God, and it is one that the poorest of us can make and be not poorer but richer for having made it.