To preach morality is like preaching to a stove

The higher worlds convey to us the impulses and powers for living, and in this way we get a basis for morality. Schopenhauer once said: “To preach morality is easy, to find a foundation for it, difficult.” But without a true foundation we can never make morality our own. People often say: Why worry about the knowledge of higher worlds so long we are good men and have moral principles? In the long run no mere preaching of morality will be effective; but a knowledge of the truth gives morality a sound basis. To preach morality is like preaching to a stove about its duty to provide warmth and heat, while not giving it any coal. If we want a firm foundation for morality, we must supply the soul with fuel in the form of knowledge of the truth.
Source: Rudolf Steiner – GA 95 – At the Gates of Spiritual Science – Lecture II: The Three Worlds – Stuttgart, 23rd August 1906