Have faith in the Buddha’s path to happiness that so many people have followed to enlightenment. Faith, in Buddhist terms, means confidence–confidence based on what you have seen so far, and confidence in what you can project to be true based on what you have seen. For example, you have personally observed that whenever you were full of negative mental states, you suffered. You recall that whenever you were full of positive states of mind, you felt happy. When all these states changed you saw their impermanence. These are facts. You can have confidence in this. This kind of confidence keeps you on course until a deep realization of truth leaves no more room for doubt.
from “Eight Mindful Steps to Happiness” pp. 154-155 (Wisdom Publications)