IMO, there is no Text on Truth as conceived in this OP. All religions conceal truth, may be not deliberately but because they are able only to provide a warped view of Truth as imagined by one or more Prophet/s, Gurus or Acharyas.
But since the mind abhors a vacuum, it has to grasp ideas, notions, thoughts, feelings, perceptions, emotions, etc. in order to build a sense of self for itself. These "ideas, notions, thoughts, feelings, perceptions, emotions, etc. are what define ME, the "ahamkaara", and they constitute who "I am" - that is the underlying construal. The more gross, heavy and burdensome the things which the mind holds on to, the more solid, substantial, well-defined and powerful the fabricated, construed self-identity feels like. That is why it is difficult to come out of some mental states like rage, jealousy, depression, egotism, superiority etc. It is not easy to give up the things that have contributed so much to the building up of one's sense of one's own self.
Individuals differ in what ideas, notions, thoughts, etc. they grasp. Ideologies, religions and gurus differ in what ideas, notions, thoughts, etc. they encourage and require their followers to take up.
The mind can latch on to base ideas like power, anger, violence, prejudice, repression, etc. like in nazism, fascism, islam and the old testament; at the other extreme, it can take up powerlessness, goodwill, submission of the extreme kind (विधेयत्व vidheyatva) and other similar things as in the Bhakthi movement/Vaishnavism and the new testament. The mind may like to grasp the dramatic magic, mystery and mysticism as in Tantrism and what many of the stories (which are mostly hearsay and not verified scientifically) circualted about the many Acharyas, Gurus, Swamis, Godmen/Godwomen, and in the stories about Jesus. It can find attraction and grasp elaborate, complicated and even masochistic rituals and the worship of deities like in everyday Hinduism and Vajrayana Buddhism. It can grasp intellectual concepts and states of meditation like in Advaita and Mahayana Buddhism.
The tendency to seek an origin (and hence the creator of) and the fundamental basis for the universe is itself a form of such mental grasping on to something in order to strengthen the mind's own building up of the sense of SELF. This is not an exhaustive list, there are a large number of other things which the mind can and does, hold on to equally vehemently in order to create its own image of the SELF. The majority of individuals, religions and ideologies grasp more than one thing.
Hence, to get at Truth, the first step is to get over all the "self-constructs" so far made by one's own mind. Deep self-contemplation is the best way to go about this. A Guru or Spiritual Teacher is a stumbling block to this and so if one wants to really seek Truth, one should avoid latching himself/herself like a flunky of any guru, acharya, godman, etc.
Ultimately, it is a complete "nothingness" and this is the Truth. Spiritual development is all about the mind becoming more and more comfortable with vacuum.
Once again, there is no text on TRUTH and there cannot be one, for the simple reason that TRUTH is beyond all human senses including the mind and the intellect, to grasp.
