“Wage the good warfare, holding faith and a good conscience. By rejecting conscience, certain persons have made shipwreck of their faith.” (1 Tim 1:18-19)
Jesus said, “Everything is possible for one who believes.” Immediately the boy’s father exclaimed, “I do believe; help me overcome my unbelief!” (Mk 9:23-24)
The apostles said to the Lord, “ Increase our faith!” (Lk 17:5)
I am amazed that you are so quickly forsaking the one who called you by [the] grace [of Christ] for a different gospel (not that there is another). (Gal 5:6-7)
May the God of hope fill you with all joy and peace in believing, so that you may abound in hope by the power of the holy Spirit. (Rom 15:13)
What good is it, my brothers, if someone says he has faith but does not have works? … Faith of itself, if it does not have works, is dead. Indeed someone may say, “You have faith and I have works.” Demonstrate your faith to me without works, and I will demonstrate my faith to you from my works. (Jas 2:14-18.)
http://ccc.usccb.org/flipbooks/catechism/index.html#62/z