In plain words
Rāma, the embodiment of Dharma, as the Yajurveda; Lakṣmaṇa as the Ṛgveda. Bharata as the Sāmaveda; and Śatrughna, who crushed the forces within and without, bore the command on his head and took the path that follows the Ātma, as the Atharvaṇaveda: so they were born. These four embodiments of the four Vedas went on showing ideals, to uplift the world and to establish Dharma.
We believe only that Rāma is an Avatāra, that He is Nārāyaṇa Himself in form, that He is the embodiment of God; but that He is a human being, an ideal figure, we cannot bring ourselves to believe. We are weaklings who cannot believe even in the principle of an ideal man; how can we believe in the principle of the Avatāra? Rāmacandra took human form, lived in human society, in the community, and made people experience an ideal daily life; man today cannot believe in Him as an ideal figure, and that he should worship Rāma as an Avatāra is simply laughable. Only when we believe in Him as one who gives us an ideal in daily life is there meaning in believing in Him as an Avatāra. The Rāmāyaṇa set Him forth entirely as the embodiment of the Trimūrti, a model of the human ideal. When the principle of the Ātma, Brahman without attributes and without form, takes on a human form, what we need most is precisely the ideal life.
In the Praṇava, which is the form of sound, what the sounds A, U and M form is the very principle called Oṃkāra. The A is Lakṣmaṇa, the U is Bharata, the M is Śatrughna, and the very union of these three has been set forth as Rāma, who is called Oṃkāra. That is, Rāmacandra is the form whose very self is the Trimūrti.
However strong a man may be in the world, however learned, however wealthy, when certain obstacles befall him he grows weak and falls into misfortune. When adversity comes, for a man to grow weak, or to sink and waste away: this is a common trait. But when such obstacles began, the one who faced them with courage and daring, overcame them and gave an ideal in many ways was Rāmacandra. In any man's life, for happiness to come without hardships is a lie. Hardships jeer at the sight of happiness. Sorrows mock at the sight of joy. These sorrows and griefs lie in wait for these joys and delights. The Manas is full of ups and downs. Our circumstances too are full of ups and downs. In such circumstances, how can a human life be lived without the ups and downs called pleasure and pain? Truly, as it is said, ‘Na sukhāl labhate sukham’: to enjoy happiness without hardship cannot be. Today we must recognise the truth that happiness and sorrow are not forms one can see.
“Hardship and happiness, both are joined as one; Hardship cannot be set apart. Happiness by itself is nowhere to be seen. When hardship bears its fruit, they call that happiness.”