When Hashem created the world, His intention was to create with middas ha-din but saw that the world could not withstand the strict judgment so he joined together middas ha-rachamim. Every Rosh Hashana, the original desire to have a world based on din is restored. That is SCARYYYY!!! How can we withstand the din?? ומי יצדק לפניך בדין??!!!
The only way to do it is to bring rachamim back into the picture. How do we do that?
Here. Including a beautiful exposition of the Gemara in the Avoda Zara [17b-18a].
