Dark times can be a source of progress in our spiritual practice, since they allow us to see clearly the difference between what truly matters in life (inner peace, altruistic love and compassion for instance) and what is just the unavoidable upheavals of any life.
Having confidence in an ethical or religious system that has at its core compassion, altruism, and wisdom can indeed be of great benefit.
In Buddhism, the Buddha is not seen as a creator, a prophet, or a saint, but as an enlightened being. Therefore, faith is a deep conviction in the example given through his life, his wisdom and compassion, and the authenticity of his teachings.
A deep sense of confidence arises from the recognition that if we apply the teachings, we will be able to face all circumstances, good and bad, with wisdom, inner strength and freedom. Once serenity and freedom has been achieved within ourselves the constant changes of outer circumstances will not unsettle our mind very much.
If we are free from craving, attachment, animosity, and from the endless preoccupations with gain and loss, praise and criticism, reputation, rank and possessions, we will be less vulnerable and become fearless.