The formation of the word 确信 is a conceptual fusion where the first character 确 (què), meaning "certain" or "confirmed", acts as an intensifier that solidifies and validates the second character 信 (xìn), which means "to believe" or "trust". It is not merely a sequence of ideas, but a layered construction where the quality of certainty is applied directly to the state of belief, thereby creating a new, unified notion of a belief that is held with firmness and conviction, resulting in the meaning "to be firmly convinced" or "to be sure".