Truth realization is a very deep topic. One might ask what truth -realization is? Truth realization is realization of the knowledge of the true self to get unity in diversity. Identifying the fact that the Soul/self is the unified Whole.
Self- knowledge is not theoretical knowledge based on the physical self [ego] but the knowledge of the ultimate truth on which the physical existence [illusion] is dependent. Self-knowledge is the True Knowledge.
v What is Self -Knowledge?
Self - Knowledge is Knowledge of the true self. Self-knowledge is required to overcome the duality. Self-knowledge comes when one learns to deeper inquire, analyze and reason on the base of the soul as self, the self- Knowledge reveals to the Seeker after Truth.
Gnanis have this self - Knowledge. People think there are many sources to acquire the self-knowledge, but fail to acquire it from many sources. Those who are lucky will follow the path of inquiry and reasoning. It is impossible to acquire Self-knowledge from any other source, other then the path of inquiry and reasoning on the base of the soul as self.
Only those serious seekers of truth do not leave a stone unturned in their quest of ultimate truth, will realize the fact that, only through inquiry, analysis and reasoning on the base of the soul as self, it is possible to acquire nondual wisdom
There is no other Reality other then realizing the fact that, the soul is the true self. Everything in the experience of diversity is created out of the soul and sustained by the soul and finally everything dissolves as soul.
Seeker has to remember self-knowledge is the Gateway to get unity in diversity. Self-knowledge is the key to know the illusion and reality are one in essence.