"Noach was a tzadik in his generation". In the times of Noach there was a lot of immorality and cheating. The generation of his time was so corrupt that Hashem decided to destroy the world with a flood. Hashem commanded Noach to build in ark for 120 years. Why couldn't G-d make an ark for Noach and save him and his family? Hashem wanted Noach to build the ark himself so people will be curious and ask Noach and then Noach will tell them what Hashems plan is and maybe hopefully they will do teshuva. Noach didn't try to stop them from sinning only when they would ask what e is building an ark for. Nowadays, we have the same situation. We say to ourselves and to others as long as I keep Shabbat I'm fine. No! You are not. The Jewish nation is connected to one another. Every sin/mitzvah we do is connected to another Jew. Without knowing we can hurt someone or help them spiritually. In our generation it is our job to save as many precious souls as we can to return to Hashem, our father, our king. It says in the Gemara that when someone saves one person it's as if they saved the entire world. Don't be embarrassed about approaching someone that what they are doing is not allowed according to the Torah. Of course you need to say it with love and understanding. Each and every one of us has the potential to be a tzadik/tzadeket in our generation however, don't forget about the people of our generation.