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