Chapter 4 – JnanaYoga
ajñaś cāśraddadhānaś ca
nāyaṁ loko ‘sti na paro
na sukhaṁ saṁśayātmanaḥ
Text Source – “http://prabhupadabooks.com/bg”
Ignorant(agnah), faithless(ashraddah), and doubtful persons(samshaya-atma) will be destroyed(vinashyathi). Not in this loka, nor in the para loka(other worlds) will the doubtful get any happiness.
When you have faith, dedication towards the scriptures, and when one follows the path they will attain peace as described in the previous verse.
When you don’t have faith, nor dedication, and you are full of doubts, then you will not find peace in life, as one can only be peaceful with knowledge. And knowledge can only be attained by perfecting karma through jnana(action with wisdom).
Out of ignorant, faithless and doubtful, doubtful is the worst.
Swamiji – one who is doubtful, he doubts everything. Even God.