How to Grow Your Soul:
https://bahaiteachings.org/divine-common-sense-grow-soul?utm_source=BT+Subscribers&utm_campaign=16902785b2-RSS_EMAIL_CAMPAIGN_NEW&utm_medium=email&utm_term=0_22fe645b0d-16902785b2-114045481&mc_cid=16902785b2&mc_eid=a5e50159ab

How can one increase in faith?  You must strive. A child does not know, in learning he obtains knowledge. Search for Truth.

There are three kinds of Faith: 

first, that which is from tradition and birth. For example: a child is born of Muhammadan parents, he is a Muhammadan. This faith is weak traditional faith: 

second, that which comes from Knowledge, and is the faith of understanding. This is good,

but there is a better, the faith of practice. This is real faith.

We hear there is an invention, we believe it is good; then we come and see it. We hear that there is wealth, we see it; we work hard for it, and become rich ourselves and so help others. We know and we see the Light, we go close to it, are warmed by it, and reflect its rays on others; this is real faith, and thus we receive power to become the eternal sons of God. 

– Abdu’l-Baha in London, pp. 64

The light of a good character surpasseth the light of the sun and the radiance thereof. Whoso attaineth unto it is accounted as a jewel among men. The glory and the upliftment of the world must needs depend upon it. – Tablets of Baha’u’llah, p. 36.