New races are created in every manvantara and the Supreme one descends as an avatara to grace and elevate these races. There is no end to these continual avataras. Meaning, the story of the Ramayana is repeated on a smaller scale with the descent of every soul into a human body. Suryanarayana, the lord residing in the physical orb of the Sun creates with his rays.
Therefore the Lord descended as Man in the house of King Dasaratha. As a child, he was playing in the palace along with his brothers. It was as if the four Vedas were playing in the forms of the four brothers. Rama was the Yajurveda which shows the path of Dharma as a pratyaksha pramana. Lakshmana, who viewed the words of Rama as mantras symbolises the Rigveda the mantras of which are chanted during a yajna.
Bharata who was devoted to Rama’s name and form and constantly sang his praises symbolises the Samaveda. Shatrugna, the one who follows the orders of the other three brothers and destroys the outer and inner enemies symbolises the Atharvanaveda.
Dasaratha performed their upanayana or thread ceremony in their 11th year and ordered for their education to begin. A river initally begins as a small stream and gathers in size by accumulating water from other streams and tributaries and then finally merges into the ocean. In the same manner, Rama had accumulated knowledge of all the available sciences by the time he was 16 years old. Kaikeyi was the first teacher who taught him Dhanurvidya or the art of archery.
This way, the four brothers were growing in strength and knowledge. Dasaratha then appointed sage Vasistha to be their teacher and they soon became proficient in multiple arts and sciences. Sage Vishwamitra approached Dasaratha for help due to the obstacles he was facing in the performance of his Yagna and was accorded a royal welcome by the King. The sage was pleased with this reception. In the meantime, sage Vasishta also reached there. There is a hidden symbolism here, Vasishta represents the Pranava or Om and Vishwamitra is the seer for the Gayatri mantra. A vision of Lord Rama becomes a possibility only when these two meet, meaning Lord Narayana, the supreme one, descends as a avatara to uplift humanity and restore Dharma on Earth.
A normal human transforms into a divine being through spiritual practices of yama, niyama etc. Those ignorant of the possibilities of a human life remain stuck in the circle of ego and emotion. Dasaratha is one of the these people. The Guru is the one who shows such a one the real indestructible IAM in himself. Vishwamitra represents this Guru. Vishwamitra is also the name given to the principle which governs the hearing organ or the ear in creation. The human Vishwamitra is but a manifestation of this divine principle in the cosmos.