Jīva Gosvāmī’s philosophical magnum opus, the Ṣaṭ Sandarbha (“six treatises) can be considered as the most conclusive and important work on Indian theology and philosophy (darśana) that answers all questions about Absolute Reality in a very systematical way.
Tattva Sandarbha is the first book of the Ṣaṭ Sandarbhas. It discusses the Reality (tattva) that is the ultimate subject to be understood and realized. It also offers a brief overview of Gauḍīya Vaiṣṇava ontology, on which its theology is based. Tattva also means “essence,” and thus Tattva Sandarbha provides the essence of what is to be elaborated upon in the rest of the Sandarbhasand serves as an introduction to them. This book can be divided into two parts, pramāṇa and prameya. The first deals with epistemology (pramāṇa), or the means of valid knowing. In it, Jīva Gosvāmī establishes the Bhāgavata Purāṇa as the foremost source of knowledge and vision of Reality. Tattva Sandarbha provides the epistemological viewing frame through which Śrīmad Bhāgavata is established as the means of valid knowing of Ultimate Reality and Bhagavān as the supreme object of divine love.
Know that whatever happens to you, good or bad, there is always a message behind it. Krishna is always trying to teach you something. He has His own way of teaching, sometimes by creating a favorable situation and sometimes unfavorable. Both are His grace.