A sacred cow is an idiom that comes from Hinduism, which worships animals. Hinduism is also known for its elevation of cows to a sacred status. In Hinduism, you do not dishonor or desecrate their sacred cows. Even today, you could be jailed or even killed for slaughtering a cow in some parts of India.
In our culture, a sacred cow is something that is considered immune from question or criticism. It is something that people hold dear and will be very angry if anyone even dares to change it or question it.
Let's call it what it is: IDOLATRY.
One more time:
SACRED COW = IDOL
And sadly, this worship of false gods is very prevalent within our churches. In ministry, sacred cows are those things that are holding back the ministry, but they are not allowed to be changed or questioned.
I have seen these revered cows in every ministry I have been involved with. As a leader, I begin to feel very discouraged and powerless against them. There have been many times where a desperate change has been needed in a ministry, but I am not allowed to touch it because it is a sacred cow to someone. Most often, I am not even allowed to question it for fear of causing division. Such is the way when you try to mess with people's idols.
So then what happens? The ministry continues down the path of idolatry. And while those few people are happy they got to keep their cow, the ministry ultimately suffers in the long run. In some cases, untold numbers of people could be reached and many others would receive a blessing if changes could be made. But because of idolatry, the ministry becomes ineffective.