好事多磨
success comes after painstaking efforts; success is always accompanied by difficulties; good things never come easy; good things happen to those who wait; trials and tribulations are always encountered before success is accomplished; no good deed goes unpunished; there is no good that does not cost a price
好事多磨hǎo shì duō mó
磨：困难。一件好事在进行之中往往要遇到许多波折。the course of true love never did run smooth, the road to happiness is strewn with setbacks, Good things are a long time in coming.