Can a Person Who Has Not Attained the First Fruit (Srotāpanna) Introduce and Explain the Buddha-Dharma to Others?

Question: Can someone who has not yet attained the first fruit (stream-entry) introduce and explain the Buddha's teachings to others? 

Answer: As long as one has some understanding of the Buddha's teachings, one can introduce and explain them to others truthfully. However, one should speak only of what one knows, and not go too far beyond one's level. Do not speak of things you are not sure about; follow the principle of "knowing what you know, and admitting what you do not know." At the same time, do not intentionally or unintentionally lead others to misunderstand that you have realized the truth. If you have not attained the fruits, do not teach others how to attain them or how to awaken to the true mind; still less should you show off and presumptuously certify others' realization, thereby misleading them. Speak according to the level of your own cultivation—do not overstep your bounds. Honestly tell others your actual level of practice; anything beyond that should be offered only as a reference, not as guidance. In this way there will be no fault. 

There are quite a few people who show off despite having no real cultivation. Such people love to flaunt themselves and to seek attention, so they often say things that go beyond their level. This is all due to severe grasping at self; the "self" in their minds is so inflated it could burst them apart. The notion of self and the notion of sentient beings are firmly entrenched and hard to break, and as a result they create evil karma such as false speech. In fact, they gain nothing from it; even if they do, it is not necessarily others' admiration and respect—merely a good feeling about themselves. Thus the afflictions and fetters of sentient beings bind their own minds so tightly that they do not know the taste of liberation—pitiable and lamentable indeed.