It is important to show gratitude.  Sometimes gratitude does not involve much effort or expenditure, so long as it is sincere.

Our Mishna on Amud Beis teaches us:

הַמּוֹצִיא הוֹצָאוֹת עַל נִכְסֵי אִשְׁתּוֹ הוֹצִיא הַרְבֵּה וְאָכַל קִימְעָא קִימְעָא וְאָכַל הַרְבֵּה מַה שֶּׁהוֹצִיא הוֹצִיא וּמַה שֶּׁאָכַל אָכַל הוֹצִיא וְלֹא אָכַל יִשָּׁבַע כַּמָּה הוֹצִיא וְיִטּוֹל

With regard to one who pays expenditures for his wife’s property in an effort to improve it, if he paid a large amount in expenditures and ate only a small amount of produce before he divorced her, or if he paid a small amount in expenditures and ate a large quantity of produce, that which he spent he has spent, and that which he ate he has eaten. Therefore, none of it need be returned. However, if he paid expenditures for the property and did not eat any part of it, he takes an oath with regard to how much he paid and then takes his expenditures.

The Alshich (Devarim 26) understand this Gemara metaphorically as applying also to God’s marriage to the Jewish people.  Bereishis Rabbah draws a comparison between the mitzvah of Bikkurim (bringing the first fruits to the Beis Hamikdash) and creation of the world.  Both use the word “Reishis - Beginning or first.”  The Midrash says, in the world was created in the merit of the mitzvah of Bikkurim.  The Alshich wonders, what is so compelling about the mitzvah of Bikkurim over all other mitzvos, that this merits the creation of the world?

The Alshich answers based on our Mishna.  God created the world to be kind to us, and of course for us to recognize this kindness.  Each year, with the influx of abundant new fruits, it is easy to become complacent and even smug, thinking that all these achievements are due to our own hard work and cleverness.  We who do not live in an agricultural society so we do not connect to the joy of experiencing first fruits, but the dynamic is the same in other successes and productions.  Be they material or intellectual, we are tempted to attribute our gifts to our own cleverness and hard work.  The mitzvah of Bikkurim is to remind us who really is the boss.  God does not ask for a large amount in tribute but a mere token. Just as in the Mishna, “if he paid a large amount in expenditures and ate only a small amount of produce” it is still sufficient.  All God wants is his rightful recognition that is due to Him, and we can keep the rest.