Olam HaZeh vs. Olam HaBa
On the topic of what is most important, let us raise an interesting question. Which world is more important, Olam HaZeh or Olam HaBa? Many people will say that Olam HaBa is the purpose and the more important world. Indeed, that is how it appears from the Mesilas Yesharim (ch.1). He writes, "The rule is: A person wasn't created to be in Olam HaZeh; he was created to be in Olam HaBa. The purpose of Olam HaZeh is just a means to reach Olam HaBa. As Chazal say, 'This world is like a hallway before Olam HaBa.'"
However, there is another side to the coin: Olam HaZeh is the world where a person can choose between good and evil. This option doesn't exist in Olam HaBa. And this aspect of free choice makes our avodas Hashem in this world so special. In this aspect, Olam HaZeh is the primary world.
The Rishonim ask why Olam HaBa isn't mentioned explicitly in the Chumash. The Vilna Gaon zt'l answers that for Hashem, Olam HaZeh is the main world. This is a shocking statement. Isn't Olam HaBa the purpose? However, in a way, this world is the primary world because this is the world of challenge. This is the world where avodas Hashem takes place.
