There is another point which is crucial and this is the conscience of the value of the offering. Because even if the offering exists, it’s value is not always obvious for the other. It’s difficult to see the light even the global when you are confined in a local darkness. The value is observable when you believe. The believer sees the source of the light and the essence. The problem is to reach this level. And the core of the problem is always that you see only what you get. Even if facts exist,  someone has to interpret this fact and for that he needs a knowledge. If this knowledge is a deep one then there is a need of teaching to understand its reality.