How can faith be developed?

Faith, from the Islamic perspective of teachings consists of a belief in heart, stated on the tongue when one expresses it and a belief that is acted upon by the limbs, not just a concept but a concept in action. It begins with knowledge, as God said in the Qur’an:

 Know, therefore, that there is no god but Allah.[1]

Thus, a person has to know. This is the beginning, to know and have the knowledge that there is no God except Allah. Without this knowledge, one may have faith in worshipping things other than God: animals, trees, etc. There are various levels of faith. Even though it may have a positive impact on people, the real necessity is the correct faith that begins with the knowledge that none has the right to be worshipped except Allah.

This raises the question as to what is worship. It's necessary to know that worship from an Islamic perspective is not merely going to the mosque and praying. That is an aspect of worship but in fact we have the whole concept defined in another verse where Allah asks Prophet Muhammad (ﷺ) to say,

"Truly, my prayer and my service of sacrifice, my life and my death, are (all) for Allah, the Cherisher of the Worlds.[2]

This means, living a life where one seeks to do everything to please God. This is the true meaning of worship that covers all aspects of life and is not limited to prayer or beseeching God just in times of difficulty. Anyone can do that. Worship involves living our entire life doing what pleases God, right from the time we wake up in the morning to the time we go to sleep at night and this requires knowledge. The simple formula to increase faith is to perform acts of obedience and good deeds which increase faith and avoid committing sins that reduces faith.

References:

[1] [Qur’an 47:19]

[2] [Qur’an 6:162]