There is a homogenous, scientific and unitive spiritual law that governs man’s life. Spirituality is the effort to know that universal spiritual law. This spiritual law or spiritual knowhow cannot be known only by reading scriptures, repeating some prayers or rituals and the like. It can be known only through a Guru, a person who knows the spiritual secret, who has the experience of truth. Since God is in the nature of Light and Consciousness, only through the medium of a human, God can communicate with human beings. Therefore, God has commissioned a brotherhood of spiritual masters or mahatmas, who come under the governance of Manu. Who is this Manu? Manu is the architect of our solar system, the first human archetype or the Adam of human race. It is through the medium of Manu, a cycle of human life is initiated in the solar system or solar family. Manu is the spiritual head of a solar family guiding the spiritual evolution of humanity. Nobody can bypass this spiritual system.
There are fourteen such Manu cycles or Manvantaras, one after the other, in a single episode of creation known as kalpa. This explains the probable existence of many other solar systems. The present age belongs to the seventh Vaivaswata Manu, whose spiritual era began approximately 120,960,000 years ago according to the system of Manvantara, the Indian cosmic calendar. The spiritual masters coming under Manu are magnificent souls who have ascended higher spiritual planes and unified with the Light of God through their effort spanning several births. They are known as Avatars. Avatar means one whose soul has ascended or transcended the stellar regions. They remain as luminescent souls in the astral world. It is said that the innumerable stars in the distant sky are such souls, whether we believe it or not. These spiritual luminaries occasionally adorn human forms and come down to the earth plane for the spiritual guidance of man. Mankind has received spiritual wisdom only through such souls. These spiritual authorities have their own spiritual incumbency according to their spiritual merit and the commission of God. Their spiritual incumbency may be for 1000, 1500, 2000, 2500, 3000, 5000 years etc. according to the civilizational requirement related to man’s spiritual evolution.
So it is wrong to say that one particular guru or prophet is the last messenger of God. There would be many such Godly incarnations even now and in future too for the spiritual evolution and spiritual guidance of man in every age. There is a calculation to the number of mahatmas who would come in this way. This spiritual system is known as Sanatana Dharma (means Eternal Religion) in Indian spirituality. In this system, all spiritual authorities that have come in the world have their own place in the historical march of humanity, but not limiting to them. That is why Indian spirituality is tolerant to other faiths and other spiritual masters too. Only such a cosmology can be the basis of a unitive religion that would take the human race to ultimate peace and harmony. This lost spiritual awareness has been restored to us in this era of spiritual churning through a great spiritual Master, Navajyotisri Karunakara Guru.