Is there happiness in spirituality? How to build faith?

The following is an excerpt from a samvaad (dialogue) session with Acharya Prashant.

राजविद्या राजगुह्यं पवित्रमिदमुत्तमम्।

प्रत्यक्षावगमं धर्म्यं सुसुखं कर्तुमव्ययम्।।2।।

rāja-vidyā rāja-guhyaṁ pavitram idam uttamam

pratyakṣhāvagamaṁ dharmyaṁ su-sukhaṁ kartum avyayam

Of sciences, the highest; of profundities, the deepest; of purifiers, the supreme, is this; realisable by direct perception, endowed with (immense) merit, very easy to perform, and of an imperishable nature.

~ Chapter 9, Verse 2

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अश्रद्दधाना: पुरुषा धर्मस्यास्य परन्तप।

अप्राप्य मां निवर्तन्ते मृत्युसंसारवर्त्मनि।।3।।

aśhraddadhānāḥ puruṣhā dharmasyāsya parantapa

aprāpya māṁ nivartante mṛityu-samsāra-vartmani

Persons without Sraddha for this Dharma, return, O scorcher of foes, without attaining Me, to the path of rebirth fraught with death.

~ Chapter 9, Verse 3

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Acharya Prashant (AP): Shri Krishna is explaining adhyātma or rāja-vidyā to Arjuna. That’s the context. So, he says that rāja-vidyā or adhyātma or self-knowledge or Brahmajñāna is the highest, the deepest, the supreme purifier, realizable by direct perception, endowed with immense merit, very easy to perform, and imperishable. And he adds, but those who do not have śraddhā for Dharma, return again and again without attaining the Truth, caught in the cycle of birth and death.

Questioner (Q): In verse 9.2, Shri Krishna has used the word ‘su-sukham’, meaning very easy, and has called this rāja-vidyā as the king of sciences. But, in my…