留得青山在,不怕没柴烧 As long as the green hills remain, there is no fear of running out of firewood. An early form, with 哪怕 in place of 不怕, appears in chapter 22 of Ling Mengchu’s Ming story collection Slapping the Table in Amazement: “Although we have met this great disaster, my son still holds his office. Once he reaches his post, all will be well.”
胜败乃兵家常事 Victory and defeat are common matters for a soldier. An idiom dictionary explains that even when something fails, there is no need to lose heart, because with renewed effort success may come next time. It cites an older form from the Old Book of Tang: “Victory and defeat are the constant condition of war. One should not give up a plan because one general has suffered a setback.”