The ignorant, the faithless, the doubting soul, perishes. For the doubting soul there is neither this world nor the other, nor happiness.

Danger of doubt. Ajñaḥ — ignorant — lacks knowledge; aśraddadhānaḥ — faithless — lacks faith; saṃśayātmā — doubting soul — lacks certainty.

Vinaśyati — perishes — indicates spiritual failure. Without certainty, there is no progress on any plane: na ayam lokaḥ — not this world (worldly failure), na paraḥ — not the other (spiritual failure), na sukham — not happiness (existential failure). Doubt paralyzes; healthy faith and skepticism are different.