When someone has lost faith, they may feel despair, disillusionment, and uncertainty. Synonyms for lost faith may include doubt, disbelief, distrust, skepticism, and atheism. Doubt suggests a feeling of uncertainty and questioning, while disbelief refers to a lack of trust or acceptance. Distrust suggests a lack of confidence or suspicion towards something or someone. Skepticism refers to a critical attitude towards beliefs or arguments, while atheism is the rejection of belief in a god or gods. Regardless of the synonym used, losing faith can have a significant impact on one's life and outlook on the world.