相信
xiāngxìn · HSK 2
believe
🤝 相 (mutual) + 信 (trust) = mutually trust → believe
相 means mutual/each-other; 信 is trust or letter (a person 亻 standing by their word 言). Together: to extend mutual trust toward someone or something, i.e. to believe or credit them.
信 — person 亻 + speech 言
信 combines 亻(person) with 言(speech), depicting a person standing by their words. The original sense is 'truthfulness' or 'sincerity'—what a person says can be trusted. From this it extended to 'believe,' 'trust,' and later 'message' or 'letter,' since a letter carries one's word.