preach to the converted
基本解释
- 对已持有相同观点的人作宣传
同根派生
英汉例句
- You needn't bother telling us how recycling helps the environment, because you're preaching to the converted. 你不必费口舌告诉我们回收利用对环境有什么好处，因为我们早就知道了。
英英字典
- to try to persuade people to believe things that they already believe