Only by being open and honest can we solve the problem.
Tips
history
This idiom comes from the Records of the Three Kingdoms (三国志), describing Zhuge Liang's open and fair governance of Shu. It originally described a leadership style of transparency.
usage
Often used as an adverb with 地: 开诚布公地说/谈 (to speak/discuss frankly). It's more formal than 坦白 (tǎnbái, candid) or 直说 (zhíshuō, speak directly).