Faith is the one which makes our perceptions & beliefs. If you have Faith in & believe in religious scriptures, words of a saint, then you shall be able to turn toward the God. It's Faith only which determines how you can mould your life. It shall be Good if you have Faith in the words of a saint or in religious books than you have Faith in people who indulge in gambling, betting etc. Choice is yours!!!!!
Below are few verses of Bhagwat Gita on Faith:
aprapya mam nivartante
mrityu-samsara-vartmani (Bhagwat Gita: Chapter Nine verse 3)
"Sri Krishna said to Arjuna: Those who are not Faithful in this devotional service, cannot attain Me, O Arjuna. Therefore they return to the path of birth and death in this material world."
"ye me matam idam nityam
mucyante te ’pi karmabhih" (Bhagwat Gita: Chapter Three verse 31)
"Sri Krishna said to Arjuna: Those persons who execute their duties according to My injunctions and who follow this teaching faithfully, without envy, become free from the bondage of the fruitive actions, gets liberated & come to Me."
"shraddhaval labhate jnanam
jnanam labdhva param shantim
acirenadhigacchati" (Bhagwat Gita: Chapter Four verse 39)
jnana-nirdhuta-kalmasah" (Bhagwat Gita: Chapter Five verse 17)
"Sri Krishna said to Arjuna: When one’s Intelligence, Mind, Faith and refuge are all fixed in the God, then one becomes fully cleansed of misgivings through complete knowledge and thus proceeds straight on the path of liberation."
"yoginam api sarvesam
shraddhavan bhajate yo mam
sa me yuktatamo matah" (Bhagwat Gita: Chapter Six verse 47)
"Sri Krishna said to Arjuna: And of all yogis, the one with great Faith who always abides in Me, thinks of Me within himself, and renders transcendental loving service to Me—he is the most intimately united with Me in yoga and is the highest of all. That is My opinion."
mayy avesya mano ye mam
te me yuktatama matah" (Bhagwat Gita: Chapter Twelve verse 2)
"Sri Krishna said to Arjuna: O Arjuna, Those who fix their minds on My personal form and are always engaged in worshiping Me with great and transcendental faith are considered by Me to be most perfect."
"ye tu dharmamritam idam
bhaktas te ’tiva me priyah" (Bhagwat Gita: Chapter Twelve verse 20)
"Sri Krishna said to Arjuna: O Arjuna, Those who follow this imperishable path of devotional service and who completely engage themselves with faith, making Me the supreme goal, are very, very dear to Me."
Jai Sri Krishna