Does overthinking lead to atheism or to certainty, what is the widely prevalent earthly paradise, and what are the metaphysical sciences?

Contemplation is a great act of worship that deepens faith if directed towards its proper domain: Allah's recited and visible signs, His blessings, and the effects of His names and attributes. However, contemplating the absolute unseen, such as the essence or quiddity of Allah, or the secrets of divine decree (Qada' and Qadar), leads to ruin.

To avoid error, the Quran must be the reference for sources of thought, and this should be through the words of respected scholars.

As for the paradise of this world, it is found in enjoying obedience to Allah, drawing near to Him, finding solace in His remembrance, and being content with His decree.

To learn about parapsychology, please refer to Fatwa no. 132059.