In Luke 20:7, they replied Jesus that they could not tell whence John's baptism is from.
They knew the different answers. They understood the consequences of the answers. But that is obviously not what they seek - to ask of it. They want self comfort if they were challenged the question, hence their answer. Obviously, those who wish not take sides, have a sense of uneasy in their self comfort, hence, they ask Jesus in order to reveal their wickedness that is born of their uneasiness.
So it is for those who do not seek further, knowing what the consequences are. But they hold whatever level of understanding they have to find comfort. And as time passed, this selfish cowardice turns into evil sin.
When we ask questions, it can never be for the knowledge of it alone, but for our own growth in spirit. Anything else, is wickedness in vanity.