Aum = The Holy Ghost
Tat = The Son
Sat = The Father
Sat Lok is fundamental goal - the prime directive - of Surat Shabda Meditation. Reaching Sat Lok is vastly more important than exploring any of the dual worlds of mind, causality and emotion (Mental, Causal and Astral Planes). Being there should always be first and foremost in our attention. It is our True Eternal Home.
Two currents descended from here and pervaded all the nether religions. In Sant Mat, Sat Purush is called the true lord and creator. He is 'Ajar' (undecaying), 'Amar' (undying), 'Avinashi' (indestructible) and ever constant. Sants are incarnations or embodiments of Sat Purush. This is the region of Dayal Purush (Merciful Being). There is eternal grace, mercy and bliss here. In this region, countless 'Hansas' (celestial beings) or devotees live in various 'Dweeps' (islands) and enjoy the bliss of Darshan of Sat Purush and subsist on 'Amrit' (nectar). There is no trace of Kal, Karma, anger, punishment, virtue, vice, suffering and retribution. For this reason, Sat Purush is called merciful.